Agate is a form of chalcedony quartz that forms in concentric layers in a remarkable variety of colors and textures.
Malachite
is a copper carbonate with distinctive green veining. Though not a
particularly hard stone, it takes an excellent polish.
Agate
is a form of chalcedony quartz that forms in concentric layers in a
remarkable variety of colors and textures. Geodes are rock cavities or
vugs with internal crystal formations.
Mali
Garnet, is one of the hybrid garnets, a mixture of grossular and
andradite garnets. The name derives from the West African country of
Mali where it was first discovered in 1994.
Alexandrite
is one of the rarest of all colored gemstones and is famed for its
color change from green in daylight to red under incandescent light.
Maw-sit-sit
is one of the more unusual gemstones in the world. It was first
discovered in 1963 and named after a village in northwestern Burma.
Almandine
Garnet, the most common garnet, is dark brownish or purplish red.
Garnet is very popular for its excellent hardness and brilliance.
Melanite is the black variety of the rare andradite garnet. It is sometimes known as titanian andradite.
Amazonite
is a gemstone variety of green microcline, a feldspar mineral. It is
named after the Amazon river in Brazil., though no deposits have been
found there.
Moldavite
is a bottle-green to brown-green gemstone belonging to the tektite
group. It is formed from condensed rock vapors after a meteorite impact.
Amber,
the fossilized, hardened resin of the pine tree, is one of the few
gemstones of organic origin. Most amber is found in the Baltic, where it
formed about 50 million years ago.
Moonstone is a unique stone that reflects light in a distinctive shimmering phenomenon known as adularescence.
Amethyst is the most precious gemstone within the quartz group. Amethyst ranges in color from pale lilac to deep reddish purple.
The
pink form of beryl was named Morganite, after the American banker and
collector J.P. Morgan. A soft pink to violet, morganite belongs to the
same family as emerald .
Ametrine is a form of quartz which occurs in bands of yellow and purple, a combination of the colors of amethyst and citrine.
Moss opal is a milky white opal with unique inclusions of green hornblende in moss-like patterns.
Ammolite is a rare gemstone of organic origin that is fairly new to the market, with commercial mining beginning only in 1981.
Mystic Quartz is the product of a new high tech enhancement process applied to colorless quartz.
Andalusite is a strongly pleiochroic gem, which means that is has different colors when viewed from different directions.
Colorful Mystic Topaz is the product of a high tech enhancement process that is stable and permanent.
Supplies
of andesine-labradorite are quite recent, with the mineral found in a
range of colors, including red, yellow, champagne and green.
Nuumite
is an opaque metamorphic rock with an iridescent play of color. Its
chief constituent minerals are gedrite and anthophyllite,
Obsidian
is a naturally occurring volcanic glass. It is formed when felsic lava
extruded from a volcano cools without crystal growth.
Aquamarine
is best known for its breathtaking range of blue colors and belongs to
the same family as emerald (beryl). Aquamarine is colored by trace
amounts of iron.
More
than any other gem, each opal is unique. No other stone has as rich and
varied a folklore. Opals are also the most delicate gems commonly worn.
Axinite
is a group of brown to violet-brown or reddish brown minerals that
sometimes occur in gem quality. Axinite is distinctive for its strong
vitreous luster.
An opal doublet consists of a slice of natural opal glued to a black backing, which causes the colour to become more vibrant.
A new high tech enhancement process using thin film deposition has created a new variety we call Azotic Topaz.
Orthoclase is a transparent yellow feldspar resembling citrine quartz or yellow beryl, found primarily in Madagascar.
Beryl
is one of the most important gem minerals. The most famous beryl is
emerald, but other beryl varieties include aquamarine, heliodor and
morganite.
Paraiba
tourmaline is a rare copper-bearing gem with a vivid neon blue color.
First found in Brazil in 1989, similar material has since been found in
Africa.
Bloodstone, also known as heliotrope, is a green gemstone dotted with bright red spots of iron oxide.
Peanut
wood is a variety of petrified wood, where the shape and structure of
the wood is pre- served when the original organic material is replaced
by quartz.
Boulder
Opal is the second most prized form of opal, after black opal. The name
derives from the fact that boulder opal is found embedded in ironstone
boulders.
Pearls
are products of bivalve mollusks (mainly oysters and mussels). They are
built up of nacre, which is mainly calcium carbonate in the form of
aragonite crystals.
Pure
calcium carbonate is colorless, but calcite is often colored by various
impurities, including iron, magnesium, manganese, zinc or cobalt.
Peridot
belongs to the forsterite-fayalite mineral series. It is an
idiochromatic gem, meaning its color comes from the basic chemical
composition of the mineral itself.
Carnelian
is a brownish red to orange variety of chalcedony quartz, colored by
trace amounts of iron. Darker colors (red-brown to brown) are often
referred to by the name Sard.
Pietersite is a breccia aggregate of hawks eye and tigers eye, with swirling colors of blue, rusty red, gold and brown.
Cassiterite
is one of the densest gem materials known. It also has a very high
refractive index, higher than zircon, sphene and demantoid garnet.
Prehnite,
a form of calcium aluminum silicate, has a vitreous mother-of-pearl
luster. Affordably priced for its size, prehnite makes distinctive and
interesting jewelry.
Chatoyancy,
the cat's eye effect, is a reflection of light by parallel fibers,
needles, or channels, which resemble the slit eye of a cat.
Pyrope Garnet is the most famous of the red garnets. Its dark, blood red color often resembles the color of ruby.
Aquamarine
is best known for its breathtaking range of blue colors and belongs to
the same family as emerald. Cat's eye aquamarine is quite rare.
Quartz
is one of the most common minerals on earth and is well known in the
gems world in its many forms including amethyst, citrine, and ametrine.
Diaspore, sometimes marketed under the name Zultanite, is a color change gem from Turkey. Cat's eye diaspore is fairly rare.
Quartz
cat's eye is quartz in which inclusions of rutile create chatoyancy or
the cat's eye effect. Usually found in colors of white, green, yellow or
brown.
Scapolite
is a sodium calcium aluminum silicate with a hardness of 5.5 to 6 on
the Mohs scale. It is named from the Greek for "stick," since its
crystals grow in columns.
A
combination of orthoclase and albite arranged in layers cause the
lovely sheen. Rainbow moonstone is another variety of moonstone that
adds a bluish hue.
Tourmaline with tiny parallel inclusions sometimes display a strong cat's eye effect when polished.
Rainbow
Pyrite is a recent find from Russia. The material comes in the form of
druzy-- a layer of miniature pyrite crystals coating a matrix.
Chalcedony
is the fine-grained variety of the silica mineral quartz. It has a waxy
luster and appears in a great variety of colors.
Rhodochrosite is usually found in an aggregate form with alternating light and dark stripes in zigzag bands.
Charoite
is a new gem on the market, first appearing in 1978. It is found only
in one location in Siberia, Russia. The swirling shapes of lavender and
violet are quite unique.
Rhodolite
Garnet is the name applied to a mixture of pyrope and almandite.
Rhodolite tends to be lighter in color than most other kinds of red
garnet.
Chrome
Diopside is colored by chromium and displays a rich forest green that
has similarities to tsavorite garnet and chrome tourmaline.
Rhodonite is a manganese iron magnesium calcium silicate, and a member of the pyroxenoid group of minerals.
Chrome
Diopside is colored by chromium and displays a rich forest green that
has similarities to tsavorite garnet and chrome tourmaline.
The
unique soft pink color of rose quartz is thought to derive from tiny
traces of titanium impurities. Rose quartz crystals tend to be cloudy
which deepens the color.
Faceted
chrysoberyl is a beautiful gem which is not as well known as it
deserves. Apart from the very good hardness (8.5 on the Mohs scale), it
has excellent luster.
Vivid
pink to red tourmaline, often with a violet tinge, is known as
rubellite. It is one of the most valuable tourmaline colors.
The
most famous and valuable cat's eye gemstone is chrysoberyl cat's eye.
It is valued for its excellent hardness (8.5) and sharp cat's eye.
Ruby
is the red variety of corundum, the 2nd hardest substance on the Mohs
scale, with a rating of 9. It is the combination of hardness and rich
color that make fine rubies so valuable.
Chrysocolla
is a hydrous copper silicate. Often confused with turquoise,
chrysocolla is found in unusual multicolor combinations as well as in
blue or green.
Ruby-Zoisite is the natural combination of ruby and zoisite crystals in a single specimen. Often used for carvings.
Chrysoprase
is a gemstone variety of chalcedony or cryptocrystalline quartz,
colored by trace amounts of nickel. Its color varies from apple-green to
deep green.
Named from the French word for lemon, citrine is yellow to gold to orange-brown shades of transparent quartz.
Rutile
Topaz is colorless topaz with inclusions that look like rutile
crystals. But the inclusions are actually limonite staining in thin
channels in the topaz.
Clinohumite
is a rare mineral and an especially rare gemstone. Only three sources
of gem-quality material clinohumite are known, in Tajikistan, Siberia
and Tanzania.
Sapphire, with its excellent hardness, second only to diamond, is one of the 4 traditional precious gemstones.
Diaspore,
sometimes marketed under the name Zultanite, is a color change gem from
Turkey recently introduced to the international market.
As
a gemstone scapolite is not well known, but it can be a very attractive
stone. Its color, which is usually a virbrant yellow to orange, pink or
violet, is its best feature.
Color-change
Garnet is a mix of spessartite and pyrope garnet. This garnet presents a
color change from brownish in daylight to a rose pink in incandescent
light.
Seraphinite
is a trade name for a particular form of clinochlore. The dark green
color of seraphinite is enhanced by a silvery and feathery shimmer
caused by mica inclusions.
Some
rare sapphires exhibit a color change under varying lighting
conditions. Color change sapphires are typically blue in natural light
and purple under incandescent light.
Serpentine is a green magnesium silicate aggregate that is used as a decorative stone or for carvings.
Precious
coral is a species of coral that grows in rocky seabottoms. Coral
exhibits a range of warm reddish pink colors ranging from salmon pink to
deep red.
Sillimanite
is an aluminum silicate, related to both andalusite and kyanite. In
fact these three minerals share the same chemical composition but
different crystal structures.
Danburite
derives its name from Danbury, CT, where it was first discovered in
1839. It is quite hard, with a rating of 7 to 7.5 on the Mohs scale.
Smithsonite
is one of two zinc-containing minerals discovered by the British
mineralogist James Smithson. The zinc silicate was named smithsonite in
his honor.
Demantoid
Garnet is the rarest and most valuable of the garnets. Found in green
to emerald green, demantoid garnet is difficult to find and is typically
found only in smaller sizes.
Dendritic
agate is a whitish-gray or colorless chalcedony with fern-like
inclusions known as dendrites. The inclusions look like plant material,
but they are actually iron or manganese.
Obsidian
is a naturally occurring volcanic glass. In some stones, the inclusion
of white crystals of cristobalite produce a blotchy pattern, known in as
snowflake obsidian.
Diamond,
the hardest known natural material, is a transparent crystal of carbon.
Diamond is famed not only for its superb hardness, but also for its
high refractive index and dispersion.
The
mineral sodalite is named for its sodium content. As a gemstone,
sodalite is usually blue, often with a violet tint, and frequently
contains white veins of calcite.
Dumortierite
Quartz is an ususual quartz that is integrown with the mineral
dumortierite. The inclusions of dumortierite give it a deep blue color
that is unique in the world of quartz.
The most valuable spessartite garnets display a bright, orange red. The best specimens come from Namibia.
Emerald is the most precious stone in the beryl group. The wonderful green color of emerald is unparalleled in the gem world.
Sphalerite
is a rare collector's gem whose claim to fame is exceptional dispersion
or fire. In fact its dispersion rating is three times as high as that
for diamond.
Fire
agate is an opaque, limonite-bearing chalcedony with an iridescence
which is created by diffraction of light by the layered structure.
Sphene
is a brilliant yellowish-green, green or brown gemstone of high luster,
unique color shades and, with brilliant cut, an intensive fire.
Fire
Opal is an unusual variety of opal from Mexico, with colors ranging
from yellow to orange and orange-red. Some fire opals are clear enough
for facets.
Due
to its excellent hardness and clarity spinel is an excellent gemstone
for all types of jewelery. Spinel is never treated in any way.
Fluorite
is a mineral with a veritable bouquet of brilliant colors that range
from purple to blue, green, yellow, colorless, brown, pink and orange.
Spodumene
is a relatively new mineral to science, with gem varieties discovered
only in the last 120 years. Spodumene occurs in white, gray, pink, lilac
and green.
Fossil
coral is a decorative material that is formed when ancient coral is
gradually replaced with agate. The proper name for this material is
agatized coral.
Diopside
is best known for the vivid green chrome diopside, but the black
diopside exhbiiting asterism or the star effect is also important.
A
recent discovery (1966), Gaspeite is a very rare nickel carbonate
mineral named for the place in eastern Canada where it was first
described.
Star
garnet is a rare and unsuual garnet, found only in Idado in the USA and
in India. It displays a four-ray star due to aligned inclusions of
rutile.
The
colorless precious beryl is known as goshenite. It is named after the
small town of Goshen in western Massachusetts where it was first
described.
Moonstone
is a combination of orthoclase and albite arranged in layers which
cause the lovely sheen. Star moonstone exhibits a stunning cat's eye or
four-rayed star effect.
Grossularite
(or grossular) garnet is a calcium-aluminium garnet. The name grossular
is derived from the botanical name for the gooseberry, grossularia.
Rose
quartz displaying asterism or the star effect is rare. The unique soft
pink color of rose quartz is thought to derive from tiny traces of
titanium impurities.
Hackmanite
exhibits an unusual phenomenon known as reversible photochromism, where
a mineral changes color when exposed to sunlight.
Star Ruby is a ruby which displays asterism, a six-rayed star that shimmers over the surface of the stone when it is moved.
Hambergite
is one of the lesser-known gemstones. It is usually nearly colorless,
with the vitreous luster of glass when cut. It is quite a hard material,
with a hardness of 7.5.
Star Sapphire is a sapphire which contains unusual tiny needle-like inclusions which produce a phenomenon called asterism.
Hematite,
an iron oxide, is typically a blackish grey. When highly polished it
can sometimes look like silver. Hematite is a remarkably dense material.
Sunstone
is a plagioclase feldspar with a unique glitter from platelets of
hematite. Typically it has a red, more rarely a blue or green, glitter.
Star sunstones are known but rare.
Hemimorphite is usually found in aggregate form with blue and white bands, or mixed with a dark matrix.
Quartz with red inclusions of lepidocrosite, hematite or goethite is often sold under the name strawberry quartz.
Hessonite is an orange-brown variety of garnet colored by traces of manganese and iron. It is sometimes know as cinammon stone.
Sugilite is an obscure and quite rare mineral named after the Japanese geologist, Ken-ichi Sugi, who discovered it in 1944.
Hiddenite is a form of spodumene containing chromium. The green color varies from a yellowish to a bluish green.
Sunstone is a type of plagioclase feldspar that exhibits a spangled appearance, due to reflections of red hematite.
Howlite
is an interesting grayish white mineral that is sometimes referred to
as white turquoise because of its distinctive veining.
Tanzanite
is a variety of zoisite. Colors range from blue to purple to green. The
highly coveted color is the deep blue which shows a purple hue
shimmering around it.
Idocrase
is also known as Vesuvianite, since it was originally found on the Mt.
Vesuvias volcano. The color is normally green, but also can be brown,
yellow, blue or purple.
Tashmarine Diopside is a brilliant yellow-green diopside from a recent discovery in Tajikistan, Uzbekistan and Western China.
The
most sought after of all natural topaz is called Imperial Topaz. Its
rich golden color with reddish and orange overtones is generally not
enhanced by any kind of treatment.
Tiger's
Eye is a type of opaque macrocrystalline quartz with a fibrous
structure. It typically displays chatoyant stripes, because structural
fibers are crooked or bent.
Pleochroism
is very pronounced in iolite and is seen as three different color
shades in the same stone: violet blue, yellow gray and a light blue.
Tiger's
Eye Matrix is the name given to a mineral aggregate in which
tiger's-eye-like structures alternate with iron oxide layers.
Jadeite is found in most colors from pure white thru pink, brown, red, orange, violet, blue, and black, to an range of greens.
Topaz
is an important gem due to its hardness and high refractive index.
Topaz comes in many colors but the blue topaz is especially popular.
Jasper is usually considered a chalcedony, but scientists put it in a group by itself because of its grainy structure.
One
of the most versatile of gems, tourmaline is found in every color. It
can show every tone from pastel to dark, and can appear in various
colors in the same stone.
Kunzite
is the pale pink-violet to light violet species of the mineral
spodumene. Kunzite is named in honor of the mineralogist George F.
Kunz.
The
green species of garnet was discovered in 1967 by British geologist
Cambell R. Bridges in the bush along the frontier between Kenya and
Tanzania.
Kyanite is a layered crystal with a luster that is vitreous to almost pearly, and is usually found in a sapphire-like blue.
Turquoise,
the blue cousin to lapis lazuli, has been known and valued for
thousands of years. The early mines in Sinai, Egypt, were already worked
out in 2000 B.C.
Labradorite is a member of the plagioclase feldspar group and displays a distinctive schiller in lustrous metallic tints.
Variscite
is a relatively rare phosphate mineral and high quality specimens are
used as gemstones and for carvings. Variscite is colored by traces of
chromium .
Lapis
lazuli has been used for thousands of years for jewelry and ornamental
objects. The unique deep blue color has never lost its attraction.
Verdite
is a light to dark green serpentine rock which is often spotted or
variegated. Most specimens come from South Africa and Zimbabwe.
The
blue variety of pectolite has become known as Larimar. A very rare
mineral, it has only been found in the Dominican Republic, where it is
first discovered in 1974.
Zircon has great brilliance and intensive fire, due to its high refractive index and strong dispersion.
Lepidolite
is a lilac-gray or rose-colored lithium-bearing mineral of the mica
group. It is one of the major sources of the rare alkali metals rubidium
and caesium.
No comments:
Post a Comment