BERYL(GOLDEN)
LISTING
DESCRIPTION
Golden beryl can range in colors from pale
yellow to a brilliant gold. Unlike emerald,
golden beryl has very few flaws. The term "golden beryl" is sometimes
synonymous with heliodor (from Greek hēlios - ἥλιος
"sun" + dōron - δῶρον "gift") but golden beryl
refers to pure yellow or golden yellow shades, while heliodor refers to the
greenish-yellow shades.
DETAILED
DESACRIPTION
Golden beryl can range in colors from pale
yellow to a brilliant gold. Unlike emerald,
golden beryl has very few flaws. The term "golden beryl" is sometimes
synonymous with heliodor (from Greek hēlios - ἥλιος
"sun" + dōron - δῶρον "gift") but golden beryl
refers to pure yellow or golden yellow shades, while heliodor refers to the greenish-yellow
shades. The golden yellow color is attributed to Fe3+ ions.[6][7]
Both golden beryl and heliodor are used as gems. Probably the largest cut
golden beryl is the flawless 2054 carat
stone on display in the Hall of Gems,
Washington, D.C.[16]
The mineral beryl is a beryllium aluminium cyclosilicate with the chemical formula Be3Al2(SiO3)6.
The hexagonal crystals of beryl may be very small or range
to several meters in size. Terminated crystals are relatively rare. Pure beryl
is colorless, but it is frequently tinted by impurities; possible colors are
green, blue, yellow, red, and white.
Deposits
Beryl of various
colors is found most commonly in granitic pegmatites, but also occurs in mica schists in the Ural Mountains, and limestone in Colombia. Beryl is often associated with tin and tungsten ore bodies. Beryl is found in Europe in Norway, Austria, Germany, Sweden (especially morganite), and Ireland, as well as Brazil, Colombia, Madagascar, Mozambique, Russia, South Africa, the United States, and Zambia. U.S. beryl locations are in California, Colorado, Connecticut, Idaho, Maine, New Hampshire, North Carolina, South Dakota and Utah.
New
England's pegmatites have produced some of the largest
beryls found, including one massive crystal from the Bumpus Quarry in Albany,
Maine with dimensions 5.5 m by 1.2 m (18 ft by 4 ft) with a mass of
around 18 metric tons; it is New Hampshire's state mineral.
As of 1999, the largest known crystal of any mineral in the world is a crystal
of beryl from Madagascar, 18 meters long and 3.5 meters in diameter.[5]
Varieties
Aquamarine and maxixe
Aquamarine (from
Lat. aqua marina, "water of the sea") is a blue or turquoise variety of beryl. It occurs at most
localities which yield ordinary beryl, some of the finest coming from Russia. The gem-gravel placer deposits of Sri Lanka contain aquamarine. Clear yellow
beryl, such as occurs in Brazil, is sometimes called aquamarine
chrysolite. When corundum presents the bluish tint of typical
aquamarine, it is often termed Oriental aquamarine. The deep blue version of
aquamarine is called maxixe. Its color fades to white when exposed to
sunlight or is subjected to heat treatment, though the color returns with
irradiation.
The pale blue
color of aquamarine is attributed to Fe2+. The Fe3+ ions
produce golden-yellow color, and when both Fe2+ and Fe3+
are present, the color is a darker blue as in maxixe. Decoloration of maxixe by
light or heat thus may be due to the charge transfer Fe3+ and Fe2+.[6][7][8][9] Dark-blue maxixe color can be
produced in green, pink or yellow beryl by irradiating it with high-energy
particles (gamma rays, neutrons or even X-rays).[10]
In the United States, aquamarines can be found at the
summit of Mt.
Antero in the Sawatch Range in central Colorado. In Wyoming, aquamarine has been discovered in
the Big
Horn Mountains,
near Powder
River Pass. In Brazil, there are mines in the states of Minas Gerais, Espírito Santo, and Bahia, and minorly in Rio
Grande do Norte.
The Mines of Colombia, Zambia, Madagascar, Malawi, Tanzania and Kenya also produce aquamarine.
The biggest
aquamarine ever mined was found at the city of Marambaia, Minas Gerais, Brazil,
in 1910. It weighed over 110 kg, and its dimensions were 48.5 cm (19
in) long and 42 cm (17 in) in diameter.
Emerald
Emerald refers to
green beryl, colored by trace amounts of chromium and sometimes vanadium.[6][11] The word "emerald" comes
(via Middle
English: Emeraude,
imported from Old French: Ésmeraude and Medieval Latin: Esmaraldus) from Latin smaragdus from Greek smaragdos - σμάραγδος
("green gem"), its original source being a Semitic word izmargad (אזמרגד) or the Sanskrit word, marakata (मरकन), meaning "green".[12] Most emeralds are highly included, so their brittleness (resistance to
breakage) is classified as generally poor.
Emeralds in
antiquity were mined by the Egyptians and in Austria, as well as Swat in northern Pakistan.[13] A rare type of emerald known as a
trapiche emerald is occasionally found in the mines of Colombia. A trapiche emerald exhibits a
"star" pattern; it has raylike spokes of dark carbon impurities that
give the emerald a six-pointed
radial pattern.
It is named for the trapiche, a grinding wheel used to process sugarcane in the region. Colombian emeralds are
generally the most prized due to their transparency and fire. Some of the most
rare emeralds come from three main emerald mining areas in Colombia: Muzo,
Coscuez, and Chivor. Fine emeralds are also found in other countries, such as Zambia, Brazil, Zimbabwe, Madagascar, Pakistan, India, Afghanistan and Russia. In the US, emeralds can be found in Hiddenite,
North Carolina.
In 1998, emeralds were discovered in the Yukon.
Emerald is a rare
and valuable gemstone and, as such, it has provided the incentive for developing synthetic emeralds.
Both hydrothermal[14]
and flux-growth synthetics have been produced. The first commercially
successful emerald synthesis process was that of Carroll Chatham. The other
large producer of flux emeralds was Pierre Gilson Sr., which has been on the
market since 1964. Gilson's emeralds are usually grown on natural colorless
beryl seeds which become coated on both sides. Growth occurs at the rate of
1 mm per month, a typical seven-month growth run producing emerald
crystals of 7 mm of thickness.[15] The green color of emeralds is
attributed to presence of Fe3+ and Fe2+ ions.[7][8][9]
Golden beryl and heliodor
.
Golden
beryl can range in
colors from pale yellow to a brilliant gold. Unlike emerald, golden beryl has very few flaws. The
term "golden beryl" is sometimes synonymous with heliodor
(from Greek hēlios - ἥλιος "sun" + dōron - δῶρον
"gift") but golden beryl refers to pure yellow or golden yellow
shades, while heliodor refers to the greenish-yellow shades. The golden yellow
color is attributed to Fe3+ ions.[6][7] Both golden beryl and heliodor are
used as gems. Probably the largest cut golden beryl is the flawless 2054 carat stone on display in the Hall of Gems, Washington, D.C.[16]
Goshenite
Colorless beryl
is called goshenite. The name originates from Goshen,
Massachusetts
where it was originally described. Since all these color varieties are caused
by impurities and pure beryl is colorless, it might be tempting to assume that
goshenite is the purest variety of beryl. However, there are several elements
that can act as inhibitors to color in beryl and so this assumption may not
always be true. The name goshenite has been said to be on its way to extinction
and yet it is still commonly used in the gemstone markets. Goshenite is found
to some extent in almost all beryl localities. In the past, goshenite was used
for manufacturing eyeglasses and lenses owing to its transparency. Nowadays, it
is most commonly used for gemstone purposes and also considered as a source of
beryllium.[17][18]
The gem value of
goshenite is relatively low. However, goshenite can be colored yellow, green,
pink, blue and in intermediate colors by irradiating it with high-energy
particles. The resulting color depends on the content of Ca, Sc, Ti, V, Fe, and
Co impurities.[7]
Morganite
Morganite, also
known as "pink beryl", "rose beryl", "pink
emerald", and "cesian beryl", is a rare light pink to
rose-colored gem-quality variety of beryl.
Orange/yellow varieties of morganite can also be found, and color banding is
common. It can be routinely heat treated to remove patches of yellow and is
occasionally treated by irradiation to improve its color. The pink color of
morganite is attributed to Mn2+ ions.[6]
Pink beryl of
fine color and good sizes was first discovered on an island on the coast of
Madagascar in 1910.[19] It was also known, with other
gemstone minerals, such as tourmaline and kunzite, at Pala, California. In December 1910,the New York
Academy of Sciences named the pink variety of beryl "morganite" after
financier J.
P. Morgan.[19]
On October 7,
1989, one of the largest gem morganite specimens ever uncovered, eventually
called "The Rose of Maine," was found at the Bennett Quarry in
Buckfield, Maine, USA.[20] The crystal, originally somewhat
orange in hue, was 23 cm (9 in) long and about 30 cm (12 in) across,
and weighed (along with its matrix) just over 50 lbs (23 kg).[21]
Red beryl
Red beryl (also
known as "red emerald" or "scarlet emerald") is a red
variety of beryl. It was first described in 1904 for an occurrence, its type
locality, at Maynard's
Claim (Pismire Knolls), Thomas Range, Juab County, Utah, USA.[22][23] The old synonym bixbite is deprecated
from the CIBJO, because of the risk of confusion
with the mineral bixbyite (also named after the mineralogist Maynard Bixby). The dark red color of bixbite is
attributed to Mn3+ ions.[6]
Red beryl is very
rare and has only been reported from a handful of locations including: Wah Wah Mountains, Beaver
County, Utah;
Paramount Canyon, Sierra
County, New Mexico;
Round Mountain, Sierra
County, New Mexico;[1] and Juab County, Utah. The greatest concentration of
gem-grade red beryl comes from the Violet Claim in the Wah Wah Mountains of
mid-western Utah, discovered in 1958 by Lamar Hodges, of Fillmore, Utah, while he was prospecting for uranium.[24] Prices for top quality natural red
beryl can be as high as $10,000 per carat for faceted stones. Red beryl has
been known to be confused with pezzottaite, also known as raspberry beryl or
"raspberyl", a gemstone that has been found in Madagascar and now
Afghanistan - although cut gems of the two varieties can be distinguished from
their difference in refractive index. [25]
While gem beryls
are ordinarily found in pegmatites and certain metamorphic rocks, bixbite
occurs in topaz-bearing rhyolites. It formed by crystallizing under low
pressure and high temperature from a pneumatolitic phase along fractures or
within near-surface miarolitic
cavities of the rhyolite.
Associated minerals include bixbyite, quartz, orthoclase, topaz, spessartine, pseudobrookite and hematite. The red color is thought to be from manganese substituting for aluminium in the beryl structure.
PRICE
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