The
Buttons
Below Will
Take You
To Our
Sales
Galleries
|
|
minerals-n-more.com
Mineral
Specimens, Gems, Jewelry & Gifts
Click
here for info about other gemstones
Click on the underlined links below,
to see items for sale
Calabrated Stones - Free Form Stones - Rough
Gold Rings - Gold Pendants - Gold Earrings - Gold Sets - Gold Bracelet
Silver Rings - Silver Pendants
- Silver Earrings - Silver Sets - Silver Bracelets
Beads - Fashion Pins - Tie Tacks - Bola Ties

The Gemstone Turquoise

Chemical composition: CuAl6(PO4)4(OH)8*5(H2O)
Hydrated copper aluminum phosphate.
Class: Phosphates
Color: Blue, green, blue-green.
Luster: dull to waxy
Transparency: opaque
Hardness: 5-6.
Refractive index: 1.62
Crystal structure: Triclinic(massive)
Crystal Habits:crystals are rarely large
enough to see,
usually massive, cryptocrystalline forms Such as nodules
Cleavage: perfect in two direction, but not often seen
Fracture: conchoidal and smooth
Specific Gravity: 2.6-2.9
Streak: white with a greenish tint
Sources: Iran (Persia), Tibet, China, Egypt,
Arizona and Southwestern United States
Associated Minerals: pyrite. limonite. quartz
and clays
Turquoise is one of the oldest known gem materials.
When turquoise first came to the attention of man is unknown. We have
archeological as well as literary references that pre date the Christian
era by five millennia. The four bracelets of Queen Zar, found on her mummified
arm, date to the second ruler of the Egypt's First Dynasty, approximately
5500 BC. Turquoise was used for beads by the Egyptians. Combined with other
ornamental stones, the turquoise was inlaid in gold by Sumerians and Egyptians
to produce very sophisticated articles of Jewelry.
Large mines were reported around 3,200 BC in the Sinai. The oldest known
source of turquoise is the Maghara Wadi mines in the Sinai Peninsula. Mining
expeditions of up to several thousand laborers were sent there annually.
These mines were worked for the pharaohs for 2000 years. They, were rediscovered
in the mid-nineteenth century and worked on and off until the beginning
of this century.
Turquoise was worn by Pharaohs and Aztec Kings. Its prized blue color, is
so distinctive that its name is used to describe any color that resembles
it. Pre-Columbian Indians used turquoise for beads and pendants. From,500
BC Burial grounds, in Central America and Mexico. Teeth were found decorated
with turquoise. A tribute to early dentistry as well as a different idea
for adornment. It was also extensively used around 200 BC, by both southwestern
US Native Americans and by many of the Indian tribes in Mexico.
The Anasazi and Hohokam mined turquoise throughout our Southwest. Absolute
evidence exists that these prehistoric people mined turquoise at Cerillos
and the Burro Mountains of New Mexico, Kingman and Morenci in Arizona and
the Conejos areas of Colorado. Turquoise was a popular trade item. We know
this because so much has been found in archeological sites. Many hundreds
of miles away from its source. A prime example is the Cerillos, New Mexico,
turquoise found with the Aztecs.
The Native American Jewelry or "Indian style" jewelry with turquoise mounted
in or with silver is relatively new. Some believe this style of Jewelry
was unknown prior to about 1880, when a white trader persuaded a Navajo
craftsman to make turquoise and silver jewelry using coin silver. Prior
to this time, the Native Americans had made solid turquoise beads, carvings,
and inlaid mosaics.
According to American Indians, the stone brought together the spirits of
sea and sky to bless warriors and hunters; a turquoise arrowhead assured
accurate aim. It was said that a fine turquoise was hidden in the damp ground
at the end of the rainbow. A Navajo belief is that a piece of turquoise
cast into a river, accompanied by a prayer to the god of rain, will cause
rainfall.
The name Turquoise:
may have come from the word Turquie, French for Turkey, because of the
early belief that the mineral came from that country (the turquoise most
likely came from Alimersai Mountain in Persia (now Iran) or the Sinai Peninsula
in Egypt, two of the world's oldest known turquoise mining areas.) Another
possibility could be the name came from the French description of the gemstone,
"pierre turquin" meaning dark blue stone.
For thousands of years the finest intense blue turquoise in the world was
found in Persia, and the term "Persian Turquoise" became synonymous with
the finest quality.
This changed during the late 1800's and early 1900's when modern miners
discovered or rediscovered significant deposits of high-quality turquoise
in the western and southwestern United States. Material from many of these
deposits was just as fine as the finest "Persian."
Today, the term "Persian Turquoise" is more often a definition of quality.
Rather than a statement of origin. The majority of the world's finest-quality
turquoise comes from the United States.
Old and New Locations
of Turquoise
The mines of Nishapur, in northeastern Iran, described
in 1300 AD as having belonged to Isaac, the son of Abraham, supplied turquoise
to Europe and Western Asia for centuries, and to the United States for years
before production ceased.
While turquoise has been produced in Tibet, China, Australia, Mexico, Peru,
Chile, Turkestan and Afghanistan, the principal source today is the Southwest
region of the United States-New Mexico, Nevada and Arizona. It has also
been found in Texas, Colorado and California.
Some of the old Southwest mines were Lander, Lone Mountain, Red Mountain,
Morenci, Bisbee, Sleeping Beauty, Old #8, Tyrone and Fox.
The Formula For
Turquoise
Chemically, a hydrated phosphate of copper and aluminum.
Turquoise is usually found in the"alteration zones," of arid or desert regions.
These zones are areas where the native, original rocks have been altered
through the intrusion of other rocks from some volcanic or other thermal
influence. The hydrothermal alteration is created by magma solutions from
deep in the earth being forced to the surface through fractures or pores
which eventually change the original rocks.
Several steps and processes are necessary to create turquoise. First there
must be a source of copper. This occurs in a rather limited number of areas
in the world. There must be a source of phosphorus CO-located with the copper.
Usually from the mineral, Apatite. Which is not always in rocks associated
with copper.
There must also be feldspar for the aluminum. Along with deep hydrothermal
alteration. Which breaks down the feldspars and frees the aluminum needed
for the turquoise. The phosphorus usually comes from phosphoric acid leached
from the Apatite, during the hydrothermal alteration.
The copper is usually introduced into the "host" rocks by the rising hot
magma. The copper readily oxidizes near the surface when it is in the hot
magma solution. It reacts freely with the aluminum and phosphoric acid to
form turquoise.
At this time other minerals enter into the turquoise structure and create
color variations. The chemical formula of turquoise is: (CuAl6 (PO4)8 4H2O)
this structure will very greatly with the introduction of Iron, Calcium,
Magnesium, Manganese, Silicon, and Zinc. These additional elements when
incorporated in the molecular structure of turquoise influence its color
and hardness. The color of turquoise can vary from a deep blue to a deep
green, with every variation of color in-between.
Generally, the more copper in the molecular structure the bluer the turquoise.
The introduction of iron causes the greener cast to the stone. Turquoise
creation is affected by many other factors too. For example; the best, hardest
turquoise is found within 100 feet of the earth's surface
This is not to say that turquoise has not been found in areas without igneous
or volcanic activity. Turquoise has been found in the Sinai and in Australia.
In these two areas it is found in sandstone and shale.
Its One other key geological activity is called silicification. It too is
an act of hydrothermal and intrusive alteration. Here silica, which is a
common associate of turquoise, is introduced into the turquoise deposit.
This addition and periods of intense heat are responsible for the hardness
of the turquoise and frequently the matrix as well.
Physical Properties of
Turquoise
Turquoise is opaque and has a Mohs scale hardness that
varies greatly. The deeply mined chalk like turquoise may only have a mohs
hardness slightly over 2. Where as a gem specimen mined closer to the surface
may be up to 6. The hardness varies due to several factors. Environment
and matrix are key. In silica verities quartz particles are present and
the stone will be hard enough for use as a gem stone. Silicification will
strengthen some of the matrix as well.
If silicification has not occurred the turquoise will likely be chalky,
porous, and soft. It will not be usable in jewelry without undergoing treatment.
Usually stabilization. Stabilization may also be used because moisture will
cause turquoise to turn toward green This can occur in the ground or in
jewelry by absorbing moisture and oils. This is not unlike blue azurite
changing to
green malachite as its creation environment increases its water content.
Turquoise must consist of copper, aluminum and phosphorus. Other elements
can replace various percentages of these and change the molecular structure.
For example, two very rare minerals, chalcosiderite (where iron replaces
the aluminum) and faustite (where zinc replaces the aluminum) do exist in
turquoise environments. Usually there will only be a partial replacement
of the aluminum with iron and zinc, thus leaving the turquoise altered only
in color.
Turquoise:
Natural, Treated & Pricing
At best This is a difficult task for even those of us who
have been around the business for many years. There are many verities of
natural and treated turquoise on the market today. Not to mention a myriad
of fake and created turquoise. To make matters even worse. There are many
different varieties from different mines, which appeal differently to many
peoples. Then there are the closed mines, which give way to the collector
type stones.
Our best advice for those interested in natural and collector
stones. Is to know your jeweler, know your source. Use jewelers and sources
like our selves who have been around a long time and intend to stay awhile
longer. It will be a better bargain in the long run.
One thing that an individual can be aware of is stabilization. A hot pin
will give off the smell of the resin and leave a deep mark in stones that
are just plastic. Many other false stones such as dyed Howelite or the new
stove top synthetics can be very deceiving.
Please take note that just plain stabilized turquoise is a natural turquoise,
usually in nugget form, that is too porous or soft to hold a luster. It
is submerged into a stabilizing compound, most likely an epoxy resin. The
natural capillary action of the porous stone draws this stabilizing compound
throughout the stone. It is then dried, cut, drilled, cabbed, etc. and prepared
for jewelry. The turquoise has not been altered. The pores of the stone
have been filled with a clear resin that makes the stone usable.
If this type of turquoise was not on the market, many jewelry artisans would
not be employed. It allows wide diversity. For example, necklaces of tiny
turquoise beads now can be made and tiny inlay is possible. Colors will
not change because the pores are sealed. It is not practical to use a high-grade
natural stone for heishe. For example, too much turquoise is wasted in the
grinding and the resultant bead will be fragile and will eventually change
color as well.
Once again there are draw backs on pricing these. Some stabilized turquoise
is "color shot" or "color stabilized", Color stabilized, is misleading because
it infers that it is the natural color which is "stabilized." This of course
is not true, color has been added. This is not necessarily bad, as jewelry
making is art, this color enhancement can improve the appearance of the
piece. It goes without saying. The value is less than if the turquoise was
naturally the color desired.
Also synthetic turquoise, frequently chemically perfect, has appeared on
the market in some quantity. This is literally stovetop turquoise. It has
a very natural matrix created by placing stones in the "batter" or sprinkling
in pyrite, etc. When the mix is cut then cabbed these foreign additives,
which are real, add to the illusion that the entire stone is natural.
As mentioned above this may not be all bad. Allot of jewelry is just fun
stuff. We use it to adorn and accessorize ourselves. These days there is
allot of turquoise jewelry on the market in the $25-$100 range. Most of
which is imported and priced well below what it should be, for just the
metal work.
Turquoise is considered a precious stone. At one time in history superior
specimens were valued by weight, more than gold. Today it ranges from a
few cents per carat to over $50.00 per carat for a superb gem stone. It
is widely regarded as our nation's "national stone."
In conclusion, there is allot of natural turquoise still on the market today
Just be aware that most of it is from currently operating mines. Such as
some of the Chinese and our own Morenci mine. These are still relatively
inexpensive. Somewhere between $2 and $5 per CT.
Perhaps a good investment for the future.
Turquoise Mirth
& Myth
Color enhancement has existed for thousands of years. In
ancient times a common way to enhance turquoise. Was to submerge the stone
in animal or vegetable oil and let it dry. It. Would then have a luster
that did not previously exist. This would not last for a very long and the
certain advent of oil stains appearing, when worn. Prompted the seller to
leave the area shortly after the sale.
Turquoise became a major trade and barter item for the early Persians. Persian
turquoise was found in ancient graves in Turkistan, and in the first to
third century AD, in graves throughout the Caucausus. Persian stones were
much coveted in Afghanistan, and as far north as Siberia.
The finest color, sometimes referred to as Persian, is an even robin's egg
blue. The ancients preferred blue because a gem-grade blue stone would not
change color (King Tut's treasures include a substantial amount of this
type of blue turquoise and it appears unchanged today.
The less hard blues would eventually shade towards green. At this point
in history green was not as good. Time has proven this wrong. Some green
hued turquoise such as Skyhorse, China Mountain (both are names given to
turquoise from China), Cerillos, Blue Gem, Fox, to name a few are ranked
in the top three grades.
Turquoise may be fashioned to include portions of the rock in which it was
found. This rock is referred to as matrix. The matrix often forms a pattern
called "spiderweb," which many people prefer. Rather than clear blue stones
without matrix.
Although not specifically mentioned in the Bible, scholars believe that
the robe worn by the high priest Aaron was adorned with turquoise. Aristotle,
Pliny and others refer to stones that must have been turquoise. After the
fourth or fifth century AD, many writings appeared discussing the stone.
Explorers such as Marco Polo took time to write about it.
Turquoise jewelry, has always been popular in the Orient. Tibet also had
it's own source of turquoise usually a green cast, very hard stone. It has
a significant amount of spider webbing. Turquoise was a highly revered item
to the Tibetans who ranked them in six grades, the most expensive valued
well above gold. Every Tibetan wore or carried a piece of turquoise throughout
life. Turquoise was used for currency in many areas of Tibet.
The history of turquoise in China dates to the thirteenth century AD Although
mining did exist, most stone came from trade with the Persians, Turks, Tibetans,
and the Mongols. Much Chinese turquoise was used for carving and in other
art and decorative ways. It never became a precious stone for the Chinese
as was Jade for example. Turquoise was unknown until the 18th Century in
Japan.
Turquoise was not of great import in early and medieval Europe. However,
as Asian conquests and incursions into Europe, occurred. Seventeenth century
Englishmen traveling there. Brought the style back with them, but not until
Victorian time was it fashionable for European women to wear the stone.
Victorian and Art Nouveau jewelry featured a good deal of turquoise.
Ancient doctors exploited the stone's medicinal potentials. These varied
from land to land and age to age. It was thought to prevent injury through
accident, prevent blindness by placing perfect stones over the eyes. It
was ground into a salve or powder. It was rubbed on or ingested to cure
stomach disorders, internal bleeding, ailments of the hip. Even for bites
and stings. From snakes and scorpions.
It found its way into the mystic arts. Its color could forecast good or
bad, predict the weather and influence dreams. It was good for nearly every
ailment including insanity. As a good luck talisman it found usage in nearly
every culture. The Egyptians also mounted turquoise in silver to treat eyes
suffering from cataract. Since the fourteenth century, harnesses of dogs,
horses and other animals have been decorated with turquoise to protect the
animal and master from falling injuries.
Turquoise has been believed to confer foresight as well as protect the
wearer from danger. In various countries, it is believed to fade when illness
or danger is near. Another belief is that a fading stone indicates a lover's
faithlessness or a friend's disaffection. In many cultures, the stone is
regarded as a harbinger of good fortune, success and health.
Aztecs and Egyptians considered it a symbol of prosperity. In India, one
was to wear a turquoise on the little finger and look at the stone after
seeing the new moon to gain great wealth. The turquoise from Iran is characteristically
an intense medium blue color and takes a fine polish. American and Mexican
turquoises range from light blue to greenish-blue to bluish-green. Egyptian
turquoise contains more green, showing greenish-blue to yellowish-green.
Turquoise was likely found and used by early man. Certainly the prehistoric
peoples of the Western hemisphere knew of turquoise. Turquoise has been
found in burial and archeological sites throughout the two continents. It
seems clear that turquoise was always considered a stone of life and good
fortune and it even had healing properties. The stone was used in religion,
art, trade, treaty negotiations as well as for jewelry. It was considered
by some tribes to be associated with life itself. Tuequoise is the Birthstone
for December & the 11th anniversary.
Top
Click Here for
More Information about the Copper Family

|