Chrysoprase is one of the rarest
gemstone varieties of chalcedony quartz.
Chrysoprase is available in many shades of green, ranging from light,
mint-green to deep apple-green. Most green gemstones are colored by chromium or
iron, but this rare form of cryptocrystalline quartz is colored by nickel
impurities. Until the introduction of another rare green-blue chalcedony known
as 'gem silica' or 'chrysocolla chalcedony', chrysoprase was considered the
most valuable of all quartz gemstones beads.
Some of the finest specimens are said to come from Central Queensland,
Australia. Fine Australian chrysoprase can possess a translucency, luster and
vivid green color reminiscent of fine quality jade.
Wednesday, May 27, 2015
Friday, May 22, 2015
Amazonite semi precious gemstone beads
Amazonite
is known as the 'Amazon stone' and was named after South America's Amazon
River, which flows through the heart of Brazil. It is a green semi precious gemstone variety of
microcline, one of the semi precious gemstone
varieties of feldspar. Amazonite is famed for its striking jade-like color
and luster. Most amazonite semi
precious gemstones are mottled, with uneven color distribution. Its
green to light bluish-green color is owed to traces of iron. Fine top-quality
amazonite can easily be mistaken for precious jade. As a variety of feldspar,
amazonite semi precious gemstone
beads is reasonably hard and is considered durable enough for most
jewelry applications. Amazonite looks best when set into silver or white gold
jewelry mountings. Amazonite semi
precious gemstone with a high saturation of color, interesting patterns
and evenly distributed color are considered the most desirable. Amazonite
jewelry is extremely popular in South American countries.
Wednesday, May 20, 2015
Natural Carnelian precious gemstone beads
Carnelian is a brownish-red
to red-orange variety of chalcedony. The
distinctive red-orange color of carnelian is a result of trace amounts of iron.
Sometimes the name 'sard' is used to refer to the darker colors of carnelian,
though there is no clear distinction between carnelian and sard.
Carnelian is one of the oldest known
gemstones. It was widely used in ancient Rome to make insignia and seals for
imprinting on letters or important documents because hot wax does not stick to
carnelian. It also is one of the birthstones listed
in the ancient Arabic, Hebrew and Roman tables, and is a birthstone for the
zodiacal sign of Virgo.
Today, carnelian is used for cabochons and
precious gemstones beads. It is
also carved to produce cameos, intaglios and other sculptures. The most
important carnelian deposits are found in Brazil, Uruguay, India and
Madagascar.
Many carnelian gemstones beads being offered
for sale on the market today are actually agate precious gemstones beads that
have been dyed and then heat-treated. But there is a way to
identify natural carnelian. The dyed agate will
display striping when held against the light, while the natural carnelian will
show a cloudy distribution of color. Natural carnelian is becoming increasingly
rare.
Carnelian was used as a talisman by people
dating back as early as the ancient Babylonians and Greeks. Many Muslims
believe that carnelian brings peace and happiness to its owner. This belief is
attributed to the fact that Mohammed wore a ring set with a carnelian seal.
Emperor Napoleon jealously guarded a carnelian seal that he found in an
Egyptian campaign and often wore as a watch charm.
Tuesday, May 19, 2015
Grossularite Garnet natural gemstone beads
The garnets are differently colored minerals
all with a common crystal structure and varying (but related) chemical
compositions, with members ranging from the common red almandite to
the rare green tsavorite and demantoid. Six common varieties of garnet are recognized based on their
chemical composition. They are pyrope, almandine, spessartite,
grossularite, uvarovite and andradite.
Grossularite garnet is a
calcium-aluminum garnet. The name grossularite is derived from the botanical
name for the gooseberry, grossularia. The grossularite group includes the light
to medium green grossularite; the cinnamon-colored hessonite; the
colorless leuco garnet; a dense opaque green garnet called hydrogrossular; and
the rare and valuable deep green tsavorite garnet,
colored by chromium. Grossularite garnet ranges in color from lemon yellow to
greenish-yellow, yellowish-green and even mint green.
Grossularite varies in hardness from 6.5 to
7.5 on the Mohs hardness scale. The
best specimens of grossularite can easily be confused with the more expensive demantoid
garnet. Garnet's good hardness combined with its absence of cleavage makes
it a very durable natural gemstone beads
for all kinds of jewelry.
Deposits of grossularite are found in a number
of locations, including Canada (Quebec), the USA (Vermont), Africa (South Africa,
Tanzania, Kenya and Mali), Russia, Pakistan and Sri Lanka.
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