Geological
Information, Specimen Content and Origin
The following crystals,
gemstones, rocks and minerals listed are the specimens that
I have used in my work. Click on the underlined words for
the
Glossary
of Geological Words and Terms
Agate: (silicon
dioxide) A form of chalcedony (below) and
cryptocrystalline
or microcrystalline
amorphous
variety of quartz.
Agates can be found worldwide in an infinite array of
colors and textures as well as having an unending amount
of designs within. These may include banding,
lacing
or dendritic
formations.
There are also many drusy
crystals
within this family of minerals.
The hardest drusy specimens
are of agate and quartz origin and they also present
themselves in a large array of colors. Agate forms in
veins
and cavities
and as crusts
in silica-rich
sedimentary
rock. Most drusy Agate specimens come from
Brazil and I cut freeform shapes from them. Agate is
without a doubt the most difficult stone that I have
ever cut due to its hardness. The hardness
is 7-8 on the Mohs
scale. Please see Jewelry Care”
notes!
Amazonite: (silica
potassium)
Amazonite is an aqua green variety of microcline
feldspar.
There is a slight iridescence
with the white and aqua banding
caused by the crystal
structure, orthoclase
feldspar and albite
minerals.
It forms in coarse granite
pegmatites.
I use this stone to cut freeform cabochons
and for inlay
work. Amazonite comes from the United States, Russia and
Madagascar and Canada as with these specimens.
Its hardness
is 5-6 on the Mohs
scale. Please see “Jewelry Care” notes!
Amethyst: (silicon
dioxide iron
manganese)
A variety of quartz
in which the color purple is the most sought after. The
purple coloring is caused by impurities
such as iron and manganese. Amethyst forms inside
veins
and cavities
of pegmatitic
and igneous
rock. Enormous, volcanic geodes,
some much larger than a man, are found filled with
dazzling crystals.
From giant single crystals to small drusy
like formations
this beautiful stone is loved and collected worldwide. I
work with setting precut faceted
and cabochon
stones and I cut freeform shapes from crystal specimens.
Amethyst can be found in many locals in the United
States, Mexico, Brazil, Canada, Africa, Russia, Nova
Scotia, South Korea, Germany and Uruguay. The hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Apatite: (calcium
phosphate
hydroxyl
fluorine
chlorine)
This composes the apatite
group. Apatite ranges in color from clear,
white, yellow, brown, red, pink, purple, blue and the
lovely greens and teal greens that you see here. It
forms in crystals
and as tabular,
columnar,
stalactitic
and massive.
Our bones and teeth are made up of this group of
minerals.
Plants also need these minerals to live. Apatite can be
found in Africa, Burma, Brazil, Canada, Germany
Czechoslovakia, India, Mexico, Norway and Spain and
Madagascar. Its hardness
is 5 on the Mohs
scale. Please see “Jewelry Care” notes!
Aquamarine: (beryllium
aluminum
silicate)
A member of the beryl
crystal
family the most valuable of all being emerald.
Aquamarine forms in pegmatitic
granites
associated with quartz,
feldspar,
muscovite,
tourmaline (below), lepidolite (below) and other
minerals
as well as silica-poor
schists
and marbles.
Looking into this stone, as a clear faceted
cut or an opaque
cabochon,
is like looking into a cool, pool of water. Aquamarine
comes from many countries such as Brazil, Africa,
Madagascar, Pakistan, Afghanistan, Russia and Sri Lanka.
Its hardness
is 7.5-8 on the Mohs
scale. Please see “Jewelry Care” notes!
Aventurine: (silicon
dioxide) A cryptocrystalline
or microcrystalline,
amorphous
variety of quartz
also known as chert
due to its opacity.
It forms in veins
and cavities
of silica-rich
sedimentary
rock. Aventurine contains inclusions
of shinny minerals
such as mica,
goethite,
hematite or fuchsite. Hematite gives it a reddish orange
color and fuschite a green. The sheen caused by these
minerals is called aventurescence,
thus the name. Its hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Azurite: (copper
carbonate
hydroxide)
Formed in rich copper veins
around the world. The beautiful royal and electric blues
give it it’s name. Azurite forms like malachite (below)
in carbonated
swirls with banding
of light to dark blue colors in cavities
and as crusts
and as incredible, sparkling drusy.
The most rare specimens
are from Bisbee, Arizona. Much drusy Azurite here comes
from China. I do my own cutting of these specimens.
Azurite is fragile and should only be set into earrings
and pendants which can worn with confidence when cared
for properly. Its hardness
is 3.5-4 on the Mohs
scale. Please see “Jewelry Care” notes!
Carnelian: (silicon
dioxide) A cryptocrystalline
or microcrystalline,
amorphous variety of quartz.
It is also a form of chalcedony (above) and forms as
veins
and cavities
in silica-rich
sedimentary
rock. Carnelian’s delicious color of reddish
orange is caused by hematite (below) iron
oxide impurities.
This beautiful stone can be translucent
or opaque
and range in color from light orange to deep reddish
brown. In ancient Greek and Roman times it was highly
valued and used in signet rings. Most carnelian comes
from Australia, South America and India. Its hardness
is 6.5-7 on the Mohs
scale. Please see “Jewelry Care” notes!
Chalcedony: (silicon
dioxide) A cryptocrystalline
or microcrystalline,
amorphous
variety of quartz.
This beautiful pale blue, translucent
stone can be found in many locations worldwide. Its
coloring is due to titanium
impurities.
Chalcedony forms in veins
and cavities
and as crusts
in silica-rich
sedimentary
rock. It may be massive
or botryoidal.
Some stones have a slight adularescence
due to layers of microscopic inclusions,
like a low shimmering light within. Its hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Chalcopyrite: (copper
iron
sulfide)
This is a natural iridescent
copper ore,
also known as "bornite and peacock ore" for its
beautiful range of colors in golds, blues, greens, reds
and purples. Chalcopyrite is found all over the world in
metamorphic,
Copper deposits.
Pyrite is also known as fool’s
gold. When cut open it is a gold color on the
inside. The colors are gorgeous and fun for jewelry
making. I cut freeform shapes only on the edges of these
stones. This colorful mineral should only be set into
earrings and pendants which can be worn with confidence
when cared for properly. Its hardness
is 3.5-4 on the Mohs
scale. Please see “Jewelry Care” notes!
Charoite: (hydrated
potassium
sodium
calcium
barium
strontium
silicate
hydroxide
fluoride)
This lovely stone displays itself with many fibrous,
swirly shades of lavender and purple. Its pearly
luster
is sometimes chatoyant.
This mineral
forms in massive
deposits
in syanite
and limestone.
There are often inclusions
of tinacksite
which appear as golden fibers
running throughout the specimen.
I cut my own freeform and cabochon
shapes from this stone. Charoite is a rare mineral and
found along the Chara River Valley in the Sakha
Republic, Siberia, Russia. A very remote area of East
Central Siberia in the Lake Baikal region. Its
hardness
is 5-6 on the Mohs
scale. Please see “Jewelry Care” notes!
Chrysocolla: (hydrated
copper
silicate)
A mineral
which is formed in oxidation
zones of copper ore
bodies worldwide. It is found as glassy botryoidal
or rounded masses and crusts
or veins.
Chrysocolla is associated with azurite (above) and
malachite (below) and can sometimes form with both of
them. Sometimes quartz
drusy
crystals
will form over chrysocolla making a much harder and more
lovely, sparkling, aqua specimen.
I cut my own shapes of this stone. Chrysocolla alone is
very soft and should only be set into earrings and
pendants which can be worn with confidence when cared
for properly. Its hardness
is 2.5-3.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Chrysoprase: (silicon
dioxide) A cryptocrystalline
or microcrystalline
amorphous
variety of quartz.
This beautiful apple green to deep green color is the
most valuable form of chalcedony (above). Its coloring
is due to trace amounts of nickel.
It forms in veins,
cavities
and as crusts
of silica-rich
sedimentary
rock associated with limestone
and shale.
Chrysoprase can be translucent
or opaque.
Its hardness
is 6-7 on the Mohs
scale. Please see “Jewelry Care” notes!
Citrine, Yellow-Orange and Oro Verde:
(silicon
dioxide)
A yellow to orange and sometimes slightly greenish
variety of the quartz
family. Citrine forms inside veins
and cavities
of pegmatitic
and igneous
rock. Enormous geodes,
some much larger than a man, are found filled with
dazzling crystals.
The crystals range in size from very large to very small
drusy
like formations.
The yellow to orange coloring is due to iron
and manganese
impurities.
Sometimes citrine and amethyst will form together
creating ametrine,
a beautiful purple and yellow gem. I work with precut
faceted
and cabochon
stones and I cut my own shapes from drusy
specimens.
Most citrine comes from Brazil. Its hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Cobalto Calcite / Cobaltan Dolomite:
(calcium
carbonate)
Calcite
has more calcium
and dolomite
has more magnesium.
The color is due to cobalt.
This incredible, natural drusy
specimen
can be found in a large array of pinks, from pastels to
mauves to hot pinks. It also presents itself in peach
and raspberry. This is by far one of my favorite stones.
Cobalto calcite forms as fillings in veins,
cavities
and as crusts.
I buy this mineral
in large crystal
surfaced chunks. First I slab
the crystal surface from the host rock and cut it into
shapes that lend themselves best to the formation.
Then I trim each piece on the edges making freeform and
triangular shapes attempting to save as much of the
specimen as possible. Found in metamorphic
limestone
in the Peoples Republic of the Congo (Zaire). It is
getting harder to find this incredible drusy, due to
strife in the region. I found less at the Tucson
Gem and Mineral Show this year. Cobalto calcite
should only be set into earrings and pendants which can
be worn with confidence when cared for properly. Its
hardness
is 3 on the Mohs
scale.
Please see “Jewelry Care” notes!
Corundum: (aluminum
oxide)
Ruby is a red variety of corundum.
It’s coloring is due to chromium
impurities.
Corundum forms in marbles, metamorphic,
igneous,
intrusive
and sedimentary
rocks, mica
schists and pegmatites.
Small pebbles are found in beach sand and stream beds.
Corundum can be found in worldwide. Its hardness
is 9 on the Mohs
scale. Please see “Jewelry Care” notes!
Cr-Amesite: (chromium
magnesium
aluminum
silicon)
This is a chromium-rich (Cr) variety of amesite, given the name
(Cr-Amasite) which is a low grade metamorphism
of aluminum and magnesium-rich rocks. It is in the
mica
group of minerals.
This pearly, metallic, drusy
type, crystal
formation
presents itself in shades of lavender and purple.
Cr-amesite is fragile and should only be set into
earrings and pendants which can be worn with confidence
when cared for properly. I slab the crystal layer from
the host rock then cut freeform shapes as the specimen
would allow. Triangular shaped cuts produce the least
amount of waste of the specimen. This lovely stone comes
from the Ural Mountains in Russia. Its hardness
is 2.5-3 on the Mohs
scale. Please see “Jewelry Care” notes!
Diamond: (carbon) diamonds can be
found in a vast array of colors. It is the hardest known
substance and has the highest melting point and the highest
refractive
index of all stones. A rough (unpolished) stone
has a greasy
luster
and when properly cut it then has an adamantine
luster.
Only 20% of diamonds are suitable for cutting as
gems.
The rest are used in industrial applications such as
cutting other Diamonds. There are tiny diamonds on the
edge of my lapidary slabbing saw. At 10 on the
Mohs
scale it is 40 times harder than corundum
which is at 9 on the scale. Please see “Jewelry Care” notes!
Diopside / Black Star: (calcium
magnesium
silicate)
It is always cut into round or oval cabochons.
The asterism
(star) has four rays two are straight and two are wavy
due to the crystal’s asymmetry.
Black star diopside also contains needle like crystals
of magnetite
(iron oxide). Diopside forms in igneous
and metamorphic
rock. It comes mainly from India and has a
hardness
of 5.5 on the Mohs
scale.
Please see “Jewelry Care” notes!
Dioptase: (copper
silicate
hydroxide)
This incredible, deep emerald green, drusy
crystal
is also one of my favorite mineral
specimens
to work with. This stone is becoming increasingly rare.
It was harder to find at the Tucson
Gem and Mineral Show this year in the quality
that you see here. It forms in arid regions as a
secondary mineral with silica
in oxidized,
copper
sulfide
deposits.
I cut freeform shapes by slabbing
the surface crystal layer off of the host rock. Then I
cut the shapes according to what the formation
will allow. Dioptase should only be set into earrings
and pendants which can be worn with confidence when
cared for properly. Dioptase is from Kazakhstan and has
a hardness
5 on the Mohs
scale. Please see “Jewelry Care” notes!
Fluorite: (calcium
fluoride)
Fluorite occurs in a rainbow of colors and some
specimens
are multicolored. The wide range of colors are due to
various impurities
which are usually hydrocarbons.
Fluorite forms in veins
and cavities
of metallic mineral
deposits
such as lead.
It is also associated with quartz
and calcite.
It is a common mineral in hydrothermal
deposits, granites,
igneous
rock, dolomite
and limestone.
This crystal
has wide industrial uses and it is the only mineral from
which the important element
fluorine
can be obtained. Fluorite can be found all over the
world in many geological environments. Its hardness
is 4 on the Mohs
scale.
Please see “Jewelry Care” notes!
Fuchsite: (hydrous
potassium
aluminum
silicate
hydroxide
fluoride)
Fuchsite is a chromium-rich
variety of muscovite.
It belongs to the mica
family of sheet
silicates. This lovely specimen
has shades of soft greens and a glittery iridescence
due to its sheet crystalline
structure. I cut my own stones in this material but it
is difficult cutting, due to it’s tough crystal
structure. Fuchsite should only be set into earrings and
pendants which can be worn with confidence when cared
for properly. Its hardness
is 3.5 on the Mohs
scale. Please see “Jewelry
Care” notes!
Garnet: (magnesium
iron
aluminum
silicate)
The garnets that you see here are pyrope,
which contains magnesium
and almandine,
which contains iron.
Garnets form in metamorphic
and igneous
rock of pegmatitic
granites
and rhyolites.
Often small garnets can be found mixed in with sand in
gravel beds and streams. They are cut in facets,
cabochons
and beads. The whole garnet
group has many colors, red, brown, black,
yellow, orange, pink, white and green. They can be found
all over the world and have a hardness
of 6-7.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Hematite / Quartz on Hematite: (iron
oxide) / (silicon
dioxide iron oxide) Hematite is the main source of mined
iron
ore. Its color range is black, silvery gray, brown,
reddish brown and red. It forms as a result of volcanic
activity and where there has been standing water or a
mineral
hot springs in the past. Hematite can be found worldwide
and has a hardness
of 5.5-6.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Hemimorphite: (hydrated
zinc
silicate
hydroxide)
Hemimorphite is a sorosilicate
mineral.
This beautiful drusy
crystal
has a botryoidal
formation.
It ranges in color from white to pale aqua to a
turquoise aqua. Zinc gives it its coloring. It forms in
near surface, zinc-rich environments, in veins,
cavities
and as crusts.
It has also been found as stalagmites
and stalactites.
I slab
the crystal surface off of the host rock and cut
freeform shapes according to what the specimen
will allow. Hememorphite should only be set into
earrings and pendants which can be worn with confidence
when cared for properly. Its hardness
is 5 on the Mohs
scale. Please see “Jewelry Care” notes!
Iolite / Cordierite: (magnesium
aluminum
silicate)
Iolite is the gem
form of cordierite
also known as “water sapphire”. Magnesium gives it its
blue violet color. It is formed in metamorphic
rock and in granites
and pegmatites.
It also presents itself in shades of yellowish gray (due
to iron
impurities).
Iolite has a strong pleochroism.
These lovely faceted
and cabochon
cuts are from Madagascar and have a hardness
of 7-7.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Kinoite: (hydrated
calcium
copper
silicate)
This incredible drusy
crystal
forms in veins and
cavities
and as crusts
over a host rock. It
has incredible, small, sparkling crystals, in an array
of true blue color, from pale to deep royal. Kinoite
is very rare. This is by far my very favorite drusy
formation.
I use it sparingly. It is found in only a few locals in
the world. Kinoite should only be set into earrings and
pendants and can be worn with confidence when cared for
properly. I slab
the surface crystal formation off of the host rock and
then cut freeform shapes as the specimen
will allow. Its hardness
is between 3-4 on the Mohs
scale. Please see “Jewelry
Care” notes!
Kyanite: (aluminum
silicate)
The mineral
kyanite is usually blue to blueish-green but can also be
white, gray or green. It has a pearly, prismatic,
translucent
luster.
A polymorph,
silicate mineral commonly found in aluminum-rich,
metamorphic
pegmatites,
sedimentary
rock and quartz
veins.
Its hardness
varies depending on its crystallographic
direction, this is called anisotropy;
(6-7 lengthwise and 4-4.5 crosswise) on the Mohs
scale. Most kyanite comes from the United
States. Please see “Jewelry Care” notes!
Labradorite: (calcium
sodium
aluminum
silicate)
Labradorite is a beautiful, splotchy, grayish mineral
with a very colorful shiller
effect when viewed slightly sideways. This is
called labradoresence.
You may see flashing colors of red, blue, violet, green,
gold and orange in a silvery, shimmer deep within. This
is caused by a play of light being reflected back and
forth from internal fracture plains and thin layers of
different feldspars.
It occurs in crystalline
masses and tabular
crystals
in silica-rich
metamorphic
and igneous
rock. I do my own cutting of this stone for cabochons
and inlay.
Labradorite is found in Labrador, Madagascar, India,
Mexico, Finland, Canada and the Scandinavian Peninsula.
Its hardness
is 6-6.5 on the Mohs
scale. Please see “Jewelry
Care” notes!
Lapis Lazuli / Lazurite: (sodium
calcium
aluminum
silicate
sulfur
sulfate
chloride)
This beautiful royal blue rock is a mixture of
minerals
also containing pyrite
and calcite.
It is formed in crystalline
marble
as a product contact
metamorphism of limestone.
It is a tectosilicate
mineral and a feldspathoid
member of the sodalite
group. Lapis lazuli first came from Afghanistan where it
has been mined for over 6,000 years. Then it was
transported to Iraq, Egypt and Europe where it was used
as architectural stone, made into jewelry and also
ground up very fine to be used as pigments. Lapis also
comes from Chile, Russia, Italy and the United States.
Lapis lazuli from Afghanistan is considered the very
best quality. I use this rough rock to cut cabochons
and do inlay
work. Its hardness
is 5-5.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Lepidolite: (potassium
lithium
aluminum
silicate
hydroxide
fluoride)
Lepidolite is member of the mica
group. It is also an ore of lithium
and forms in high lithium granite
masses. It is pale pink to violet pink. Small glittery
sparkles can be seen within the layers of this lovely
stone. I use this mineral
to cut cabochons
and do inlay
work. Lepidolite comes from Brazil, Russia, Africa and
the United States. Lepidolite should only be set into
earrings and pendants which can be worn with confidence
when cared for properly. Their hardness
is 2.5 on the Mohs
scale. Please see “Jewelry
Care” notes!
Malachite: (copper
carbonate)
Malachite is a secondary copper
mineral
found in oxidized
copper deposits.
It can also form with or alongside azurite (above).
Copper causes the green color and limestone
caused the carbonation which makes the mineral grow in
bubbly formations.
When malachite is cut open you can see alternating bands
and swirls of shades of green from light to dark. Some
specimens
can also show chatoyancy
such as Bisbee, Arizona malachite. I use rough malachite
to cut cabochons
and for inlay
work. Malachite should only be set into earrings and
pendants which can be worn with confidence when cared
for properly. It is found in Africa, Russia, Mexico,
England, France and the Southwestern United States. Its
hardness
is 3.5-4 on the Mohs
scale. Please see “Jewelry Care” notes!
Moonstone: (potassium
sodium
calcium
aluminum
silicate)
Moonstone, a variety of feldspar,
occurs in a variety of colors, white, peach, light blue,
green, yellow, gray and even orange and reddish. The
different colors are due to inclusions
of different feldspar layers. Adularia
(potassium aluminosilicate of gemstone quality) is the
most common feldspar in Moonstone and it has a
shimmering play of light reflecting internally, known as
adularescence.
As the stone moves it shows a one half or a crescent
moon shape. Moonstone is always cut in cabochon
ovals and rounds. It comes from Sri Lanka, Europe,
Brazil, Madagascar, Australia and the United States. Its
hardness
is 6 on the Mohs
scale. Please see “Jewelry
Care” notes!
Mother of Pearl: (calcium
carbonate)
A natural occurring organic-inorganic
composite which forms on the mantle tissue of certain
species of mollusk. This is the way the shell protects
itself from parasitic organisms. It is composed of
platelets of Aragonite (Calcium Carbonate crystals). The
layered formation
makes a strong and resilient material. This beautiful
shell has a lovely pearly luster
which displays a variety of soft colors. Mother of Pearl
is found in Asia, Japan, Pacific regions, Europe and the
United States. It is soft and should only be set into
earrings and pendants which can be worn with confidence
when cared for properly. Please see “Jewelry Care” notes!
Obsidian / Snowflake Obsidian:
(silicon)
/ (silicon
dioxide)
Obsidian is formed when volcanic lava flows into water
forming a natural glassy stone. It can be found in a
banded
rainbow of color, it can also be translucent
or opaque,
dark green, brown or black. It can be a deep caramel red
or a black with white snowflake shapes sprinkled all
through it (snowflake obsidian). Tristobalite
crystal
is the impurity
responsible for the lovely snowflake effect. Other
impurities such as (iron,
magnesium,
etc.) which were present during formation
have given obsidian its wonderful variety of
presentation. Ancient people used obsidian for cutting
tools, spear and arrow heads because the stone could be
struck and shaped easily to bare it’s natural fracture
plains which can be razor sharp. People who shape stones
in this manner are known as Flintknappers.
A multitude of these ancient tools have been unearthed.
I do my own cutting of this stone for cabochons
and inlay
work. This volcanic glass can be found all over the
world. The hardness
of Obsidian is 5-5.5 on the
Mohs
scale. Please see “Jewelry Care”
notes!
Onyx: (silicon
dioxide)
A cryptocrystalline
or microcrystalline
member of the quartz
family. It forms in bands of black, white, gray
or brown. Banded
colors of reds and browns are known as sardonyx. This
stone is usually cut into cabochons
and beads and sometimes opaque
facets.
Onyx can be found all over the world. It’s hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Pearls: (calcium
carbonate)
Pearls are produced by mollusks and pearl oysters. Layer
by layer a coating is built up around a grain of sand
which causes an irritation inside the creature. This
coating protects the sensitive inside of the mollusk. As
the layers build their fineness determines their luster.
The iridescence
that some pearls display is caused by the overlapping of
successive layers which break up light falling on the
surface. Pearls are often white but also form naturally
in a rainbow color. Pearls are found worldwide. Please
see “Jewelry Care”
notes!
Petrified Oak / Maple Wood:
(silicon
dioxide)
Petrified
wood is a type of fossil.
It consists of fossil wood where all the organic
materials have been replaced with minerals
while retaining the original structure of the wood. The
petrification process occurs underground, when wood
becomes buried under sediment.
Mineral-rich water flowing through the sediment deposits
minerals in the plant’s cells and as they die away stone
forms in their place. The wood is preserved due to a
lack of oxygen. The vast array of colors in petrified
would are caused by elements
such as; carbon,
cobalt,
chromium,
copper,
iron
and manganese.
Specimens
can be found worldwide and the hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Pietersite: (sodium
iron
magnesium
silicate
hydroxide)
Pietersite is found in only two locations worldwide,
Africa and China. The mine in China has stopped
producing because it has been flooded, which now makes
this beautiful stone even more rare. Pietersite is
formed form crocidolite
a form of asbestos
or variety of riebeckite.
It is pseudomorphed
by quartz.
The asbestos mineral
fibers in this specimen
are replaced atom by
atom with silica
producing a very durable stone. It is formed when the
golds of tigereye (below) and or the blues of hawkeye
(blue tigereye) are broken during Earth’s geological
processes. The tiny fragments are then cemented back
together by quartz creating very interesting patterns of
fibrous chatoyancy.
These cabochons
are from Namibia, Africa and they are a 7 on the
Mohs
scale. Please see “Jewelry Care” notes!
Peridot: (magnesium
iron
silicate)
A gem
variety of olivine,
peridot is one of the few gemstones
that presents itself in only one color range. The color
is due to the Iron
content in the crystal
structure. The color can range from yellow-green to
olive to brownish green. Olivine is abundant in the
Earth’s crust but peridot is rather rare. This gem is
formed in igneous
rock and has also been found in iron-nickle
meteorites. Peridot can be found in many states in the
U.S. as well as China, Africa, Mexico, Norway, Pakistan,
Saudi Arabia, Sri Lanka, Australia and Brazil. Its
hardness
is 6.5-7 on the Mohs
scale. Please see “Jewelry Care” notes!
Quartz, Clear - “Rock Crystal”:
(silicon
dioxide)
Quartz
is the most common mineral
found in the world. It is found in almost every
geological
environment. There are many varieties, colors and forms
of quartz. It forms in cavities
and veins
of granites,
pegmatitic,
igneous
and intrusive
rock. Formations
can range in size from cryptocrystalline
or microcrystalline
to gigantic. Varieties are determined by character
rather than by color. Clear quartz or “Rock Crystal” is
free of impurities
and has many uses in the gem
trade and industrial applications as well. This stone is
usually cut into beads and it’s hardness
is 7 on the Mohs
scale. Please see “Jewelry Care”
notes!
Quartz, Lemon: (silicon
dioxide)
A lemon yellow variety of the quartz
family unlike citrine which has more orange
tones or “Oro Verde” citrine (citrine above) which has a
greenish-yellow coloring. Amethyst (above) is a purple
variety of the same. The coloring of lemon quartz is due
to iron
oxide
impurities.
Quartz forms in cavities
and veins
of granites
and in pegmatitic,
igneous
and intrusive
rock. It can be found worldwide but Lemon Quartz is
mined in Brazil and some crystals
can be very large. This lovely gemstone
is usually cut into faceted
stones and beads and has a hardness
of 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Quartz, Rose: (silicon
dioxide)
Pastel pinks and roses are present in this variety of
the quartz
family. The coloring is due to iron
and titanium
impurities.
Rose quartz is usually found with inclusions
and flaws
which give this stone it’s cloudiness and character. It
is usually cut into cabochons
and beads or used for carving. Rose quartz can be found
worldwide in very large crystal
formations.
When broken up they can be as big as landscape boulders.
I have some in my back yard! Most of the best Rose
Quartz comes from Brazil and its hardness
is 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Quartz, Smokey: (silicon
dioxide)
This is a smokey-brown to black variety of the
quartz
family. There are some varying ideas as to what
gives this crystal
it’s coloring. Aluminum,
titanium,
iron,
manganese
or carbon
impurities
as well as the actions of radium
radiations
are all possible. Quartz forms in cavities
and veins
of granites,
pegmatites
and igneous
rock. Some specimens
can be gigantic in size. Most gem
quality Smokey Quartz is cut into faceted
stones and beads. It is found worldwide and has a
hardness
of 7 on the Mohs
scale. Please see “Jewelry Care”
notes”!
Rainbow Pyrite Drusy: (iron sulfide) A rare drusy mineral found only in Russia on
the banks of the Volga River. The drusy crystals present themselves in a
rainbow of colors, greens, reds, golds, blues and
purples. This incredible drusy has a hardness of 6-6.5 on the Mohs scale. Please see "Jewelry Care" notes.
Rhodochrosite: (manganese
carbonate)
Rhodochrosite gets its luscious range of reddish to pale
pinks from iron,
magnesium,
calcium,
zinc
and or cobalt
impurities.
Each locality will have different impurities giving the
specimens
a variety of pink colors. Some will form as solid
blood-red crystals
and some in carbonated
bubbles with alternating banding
and lacing
of varying widths and shades of pinks. Other formations
will grow as crusts
over host rocks
and some will form as stalagmites
and stalactites
in caverns. I cut rough rhodochrosite into cabochon
and freeform shapes for inlay
work. Rhodochrosite comes from Colorado, Romania, Africa
and Argentina. It’s hardness
is 3.5-4 on the Mohs
scale. Please see “Jewelry Care”
notes!
Rhodonite: (manganese
iron
magnesium
silicon
calcium)
Rhodonite can present itself in a variety of beautiful
opaque,
pink colors and it often has brown or black iron or
manganese veins
running through it. It forms in grainy
masses and columnar
aggregates
in granites
and igneous
rock. Rhodonite is a minor ore of
manganese. I cut rhodonite in freeform shapes for
inlay
work and cabochons.
It is found in the USA, Sweden, Russia, Australia and
New Zealand and has a hardness
of 6 on the Mohs
scale. Please see “Jewelry Care” notes!
Seraphinite / Clinochlore:
(magnesium
iron
aluminum
silicate
hydroxide)
Seraphinite is a variety of clinochlore,
which forms from the metamorphic
and hydrothermal
alterations of iron and magnesium silicate minerals,
and can be found worldwide. However Seraphinite is a
fairly recent discovery from the Lake Baikal region in
Eastern Siberia, Russia where charoite
is also found. This beautiful opaque
stone has a silvery, pearly luster
and comes in shades of olive greens and rich golden
browns. Seraphinite is a wonderfully chatoyant
specimen
and should only be set into earrings and pendants which
can be worn with confidence when cared for properly. Its
hardness
is 2-2.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Serpentine Group: Approximately twenty
varieties of hydrous phyllosilicate minerals which may contain
(magnesium iron chromium manganese cobalt nickel) found in surface soils
high in clay. Formed during metamorphism of wet ultramafic rocks. It is used in
carving and jewelry. Most serpentines are opaque to
translucent with a vitreous, silky or greasy
luster. They are microcrystalline and massive in their growth habit. Serpentine ranges in
color from white to grey, yellow to green, brown to
black and often will contain a splotchy mix or veins
of other minerals in a variety of colors and
composition. It is found worldwide and has a hardness of 2.5-4 on the Mohs scale. Please see "Jewelry Care" notes!
Sugilite: (potassium
sodium
lithium
iron
manganese
aluminum
silicate)
Sugilite is a rare and complex mineral
which presents itself in many shades of pinkish-purples,
from pale to deep. It will sometimes display banding,
blotches or spots of many shades of these beautiful
purples. It can be translucent
to opaque.
It forms as massive
chunks in intrusive
rock and manganese deposits.
Manganese and lithium
give this stone its lovely color. Sugilite can be found
in Africa, Japan, Canada, Italy, Australia and India.
This is a very tough stone and can be worn in any
jewelry item. Its hardness
is 6-6.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Thulite: (hydrous
calcium
manganese
aluminum
silicate)
This lovely rose colored, opaque
stone is often mottled or layered with white calcite.
Manganese
gives it its rose color. Thulite forms in veins
and fractures
of metamorphic
igneous
rock and calcium-rich
metamorphosed sediments.
It is a very tough stone and can be made into any
jewelry item. It can be found in Norway, Austria,
Australia, Canada, Germany, Italy, Japan, North Korea,
Poland, Sweden, Switzerland and in several locals in the
United States. It has a hardness
of 6.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Tigereye: (silicon
dioxide)
Tigereye is a form of chalcedony (above) which is in the
quartz
family. It is a cryptocrystalline
or microcrystalline
fibrous
aggregate.
This stone began as crocidolite
a form of asbestos.
The mineral
fibers over time were silicified
an example of pseudomorphous
replacement. Iron
impurities
give tigereye beautiful gold and brown colors. The
fibrous nature gives it a wonderful chatoyancy.
Tigereye is usually cut in cabochons
and beads. I use rough material for freeform cuts and
inlay
and I also use precut, calibrated
cabochons. It can be found in Australia, Canada, China,
Namibia, India, Burma, Africa and the United States. It
has a hardness
of 7 on the Mohs
scale. Please see “Jewelry Care” notes!
Topaz, Blue: (aluminum
silicate
fluoride
hydroxide)
Topaz crystals
present themselves naturally in a variety of colors due
to various impurities.
The most common color is clear without impurities. It is
formed in silica-rich
pegmatitiic
and igneous
rocks of granite
and rhoyolite.
Iron or
cobalt
impurities could be responsible for natural blue
coloring. However natural blue is very rare. Natural
gray-blue and silver-gray topaz stones are gama-ray
irradiated and heat
treated to bring out a range of blue hues. This
treatment does not affect the hardness
or durability of the stone. This gem can
be found worldwide. Its hardness
is 8 on the Mohs
scale. Please see “Jewelry Care” notes!
Topaz, Neutral / Champagne: (aluminum
silicate
fluoride
hydroxide)
Topaz crystals
present themselves naturally in a variety of colors due
to various impurities.
The most common color is clear without impurities. It is
formed in silica-rich
pegmatitic
and igneous
rocks of granite
and rhoyolite.
Magnesium
impurities could be responsible for this natural,
champagne coloring. They have not been treated. This
gem can
be found worldwide. Its hardness
is 8 on the Mohs
scale. Please see “Jewelry Care” notes!
Topaz, Pink: (aluminum
silicate
fluoride
hydroxide)
Topaz crystals
present themselves naturally in a variety of colors due
to various impurities.
The most common color is clear without impurities. It is
formed in silica-rich
pegmatitic
and igneous
rocks of granite
and rhoyolite.
Sodium,
lithium
or potassium
impurities could be responsible for natural pink
coloring. Natural yellow and orange-brown topaz can be
heat
treated to bring out a beautiful pink color.
These treatments are permanent and do not affect the
stone’s hardness
or durability. Topaz can be found worldwide. Its
hardness is 8 on the Mohs scale. Please see
“Jewelry Care” notes!
Topaz, Twilight: (aluminum
silicate
fluoride
hydroxide)
Topaz crystals
present themselves naturally in a variety of colors due
to various impurities.
The most common color is clear without impurities. It is
formed in silica-rich
pegmatitic
and igneous
rocks of granite
and rhoyolite.
Magnesium
impurities could be responsible for natural yellow
coloring. Natural clear and yellowish topaz is often
enhanced
with a colorful vapor
coating, by applying a thin layer of
titanium
dioxide. These gems
have a beautiful, rainbow play of warm colors. This
enhancement does not affect the stones hardness
or
durability. Topaz can be found worldwide. Its hardness
is 8 on the Mohs
scale. Please see “Jewelry Care” notes!
Topaz, White / Silver: (aluminum
silicate
fluoride
hydroxide)
Topaz crystals
present themselves naturally in a variety of colors due
to various impurities.
The most common color is clear without impurities. This
clear form is sometimes called silver topaz. It is
formed in silica-rich
pegmatitic
and igneous
rocks of granite
and rhoyolite.
Topaz can be found worldwide. Its hardness
is 8 on the Mohs
scale. Please see “Jewelry Care” notes!
Tourmaline, Green-Verdilite: (aluminum
borosilicate)
Tourmaline crystals
present themselves in a variety of colors due to various
impurities.
Green tourmaline contains trace amounts of chromium
and is called verdelite.
However crystals can develop with two or more colors in
a formation.
They are common as late stage crystallization
products of granites,
particularly pegmatites,
that have been enriched by boron
solutions. Tourmalines also form in some igneous
and metamorphic
rocks and as grains in sediments.
They will form as radiating
clusters and as isolated crystals with
quartz, muscovite and feldspars.
Some are transparent
and others translucent.
Tourmaline can be found worldwide. It has a hardness
of 7-7.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Tourmaline, Pink-Rubellite: (aluminum
borosilicate)
Tourmaline crystals
present themselves in a variety of colors due to various
impurities.
Pink tourmaline contains trace amounts of manganese and is called rubellite.
However crystals can develop with two or more colors in
a formation.
They are common as late stage crystallization
products of granites,
particularly pegmatites,
that have been enriched by boron
solutions. Tourmalines also form in some igneous
and metamorphic
rocks and as grains in sediments.
They will form as radiating
clusters and as isolated crystals with
quartz,
muscovite
and feldspars.
Some are transparent
and others translucent.
Tourmaline can be found worldwide. It has a hardness
of 7-7.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Turquoise: (hydrous
phosphate
copper
aluminum)
A cryotocrystalline
mineral
associated with copper deposits.
This beautiful opaque
stone, which has been mined throughout history, presents
itself in a wide range of colors from deep blues to blue
greens to yellow greens. Copper impurities
will cause Turquoise to be more blue. The coloring of
greener and paler specimens
is due to iron
replacing aluminum and or dehydration. The phosphorous
may come from apatite (above) and the aluminum from
feldspar.
Turquoise is usually found in arid regions and forms as
a pseudomorph
relatively close to the surface in cavities,
veins
and as crusts.
It forms as a result of acidic, aqueous
solutions percolating down through preexisting
copper carbonate
minerals
such as azurite (above) and malachite (above). The
richness of a deposit determines the richness of color
in this lovely stone. One of the most valuable and rare
forms of turquoise is from Bisbee, Arizona. Its color is
of the deepest blue and often displays itself with a
dark iron-red, spider web veining known as matrix.
Pyrite
chunks and veins can also be matrix in other turquoise
specimens. The matrix can often be an indication as to
the mine of origin. There is also a beautiful almost
matrix-free Turquoise known as “Sleeping Beauty” from
Globe Arizona, which I love to use in my inlay
work. I work with only natural Arizona Turquoise.
Turquoise is found in many places worldwide especially
in the American Southwest and has a hardness
of 5-6 on the Mohs
scale. Please see “Jewelry Care”
notes!
Uvarovite / Chrome Garnet:
(calcium
chromium
silicate)
This beautiful, green drusy
crystal
formation,
is one of my favorites, and a member of the garnet
group. Drusy crystals have an incredible layer
of small, sparkling crystals (granular
aggregates)
that form on the surface of a host rock.
Uvarovite is the only green garnet in the group and is
found in crystalline
marbles
and schist.
It also presents itself in dark green to blackish green.
Chromium is responsible for its coloring. I slab
the surface crystal layer from the host rock and then
cut smaller pieces, trimming the edges, as the formation
will allow. This lovely crystal should only be set into
earrings and pendants, which can be worn with confidence
when cared for properly. It is a relatively rare
mineral
and can be found in Africa, Canada, Finland, Norway and
Spain. Most Uvarovite comes from Russia. It has a
hardness
of 7.5 on the Mohs
scale. Please see “Jewelry Care”
notes!
Vanadenite: (lead
chlorovanadate
calcium
phosphorous)
Vanadenite is a mineral
belonging to the apatite
group of phosphates.
It is formed by the alteration of lead ore by water.
Unlike the blues and greens of apatite,
vanadenite presents itself in a range of orange-red to
orange-brown to orange-yellow crystals.
Some specimens
may have all of these colors. I cut these beautiful
drusy
formations
by first slabbing
the crystal surface off of the host rock then cutting
free form shapes. These crystals are delicate and should
only be set into earrings and pendants, which can be
worn with confidence when cared for properly. Vanadenite
is found in the American Southwest, Africa, Argentina,
Austria, Scotland, Spain and Russia. Its hardness
is 2.5-3 on the Mohs
scale. Please see “Jewelry Care”
notes!
Variscite: (hydrated
aluminum
phosphate)
Variscite is a lovely green mineral
which is sometimes confused with turquoise (above). They
are very close in composition, but variscite does not
have any copper
in it. Variscite presents itself in a range of greens
from pale to emerald. It has patterns and matrix
similar to that of turquoise, also in varying shades
from creamy white to black. The matrix can form spider
web veining, again making it similar to turquoise.
Variscite forms with phosphate bearing water that has
reacted with aluminum-rich rocks
in a near-surrface environment. It occurs as cavity
fillings, veins
and crusts.
I cut and use Variscite for cabochons
and inlay
work. Variscite can be found in Utah, Germany,
Australia, Poland and Brazil. Its hardness
is 4.5 on the Mohs
scale. Please see “Jewelry Care” notes!
Wulfenite: (lead
molybdate)
Wulfenite crystals
are very popular with collectors worldwide because of
the unusual habit
of their formation.
Crystals will present themselves in a wide range of
color from deep red-orange, to orange, to caramel yellow
and even slightly greenish. The size and thickness of
the crystals covers a wide variety as well. Wulfenite,
formed by the action of near surface water, consisting
of secondary minerals,
formed by the alteration of lead ores,
with molybdenum
or tungsten.
Formations will grow in veins
and cavities
and as granular
aggregates
(drusy).
I slab
the crystal layer from the host rock
and just trim the edges in freeform shapes. These
crystals are delicate and should only be set into
earrings and pendants which can be worn with confidence
when cared for properly. Wulfenite can also be found in
Africa, Arizona, New Mexico, Mexico and Chile. It has a
hardness
of 2.5-3 on the Mohs
scale. Please see “Jewelry Care” notes!
Personal Note Re:
Wulfenite:
When I was a little girl, between the ages of four and six,
my family lived at the small, but world renowned, Glove Mine (read: Into Arizona) in the
Santa Rita Mountains of southern Arizona. The Glove
Mine is well known for its high quality wulfenite
crystals
(above). My father worked in the mine for two years
along with his brother who was part owner at the time.
They were there to gather wulfenite crystals to trade
and sell. The mine was carved straight into the mountain
on flat ground and then towards the back a shaft went
down deep into the ground. I still remember the the cool
darkness and the smell of the inside of the mine. The
delicate crystals that came from the mine were
beautiful, translucent
butterscotch and orange in color and some formations
were large, and even transparent.
The best crystals that they found are in the
Smithsonian
National Museum of Natural History. See: Wulfenite crystals. See
also: the Smithsonian's Department of Mineral Sciences Collection
Page- type in (Glove Mine wulfenite), for the
actual record.
The above information has been compiled and written by
Marilyn Mack and is under
copyright.
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