Sunday, December 5, 2010

About Turquoise


With December now here I decided to take the time to learn a bit more about this festive month's birthstone.  The traditional birthstone for December is turquoise although in modern times other gemstones such as blue zircon and blue topaz are also included.  Turquoise is a beautiful gemstone and is often paired with sterling silver.  It also pairs well with contrasting stones such as coral as in the earrings I made below:
Lampwork, Coral and Turquoise Sterling Silver Earrings




About turquoise: Colors range from sky blue to blue-green to apple green.  Pure blue colored turquoise is the most rare and most valuable.  Most stones, however, will have brown, dark gray or black veins of other minerals called matrix.  Matrix are actually deposits of other minerals such as iron found in the rock that the turquoise formed in.  Turquoise is mined in Afghanistan, Argentina, Brazil, China, Iran, Israel, Mexico, Tanzania, and the U.S.  Turquoise has been a treasured gemstone by many cultures for many centuries.

History of turquoise: Ancient Egyptians favored turquoise for their Pharaohs.  Ancient Chinese culture placed turquoise second only to jade. It was also very popular during the Victorian era in Europe.  Native Americans mined and cut turquoise to create beautiful jewelry centuries before the European settlers first arrived.

Legend & Folklore: According to folklore, turquoise is a good-luck charm and promotes good fortune, happiness and a long life.

Types of turquoise (in order of value):
Natural turquoise:  This is the most valuable and most expensive form of turquoise.  The most perfect and hardest stones are taken directly from the mine, then cut and polished without any further treatments or compounds being applied.  Natural turquoise is usually a vivid blue with a fine pattern and distribution of veins.  Natural turquoise represents less than 3% of the world market.  Natural turquoise jewelry will deepen in color as it is worn over time when oils from the skin are gradually absorbed into the stone.

Stabilized turquoise:  This is one of the most common forms of turquoise used in jewelry today.  It is less expensive than natural turquoise but is still very beautiful and more valuable than dyed turquoise (as described below.)  Stabilizing is a process applied to moderate to lower quality stones that have a softer and more porous surface.  These stones are stabilized by infusing them with a clear epoxy resin which hardens the surface and enhances the color.  Unlike natural turquoise which deepens in color over time, stabilized turquoise has a permanent color because of the hardened surface.

Treated turquoise:  This form of turquoise is dyed in addition to being stabilized as described above.  The dying of the stone can result in a somewhat artificial appearance.  Treated turquoise is less valuable and less expensive than stabilized forms.

Reconstituted turquoise:  Often called chalk turquoise, this is the least expensive form of turquoise.  Very soft lower grade chalk turquoise is ground into a powder.  An epoxy resin and dye is applied to the powder which then forms into a thick paste.   It is then pressed into forms and molds and allowed to harden.  Finally it is cut and carved into various shapes and sizes for jewelry making.  This form of turquoise is typically easy to identify  because it usually lacks the characteristic veins or matrix; beware however since some manufacturers have now begun to use resins to simulate the matrix found in natural and stabilized turquoise. 

Synthetic turquoise:  This is actually not turquoise at all but other stones, bone, ceramic or even plastic that has been dyed to look like turquoise. 
Remember,  a reputable dealer will provide a description of the type of turquoise being sold!
Sleeping Beauty Turquoise:  Sleeping Beauty turquoise is mined from The Sleeping Beauty Turquoise Mine in Arizona.  It is one of my favorite turquoise varieties!  Sleeping Beauty Mountain, where this mine is located, was once a gold and copper mine but is now used to mine some of the best turquoise in the world.  Sleeping Beauty turquoise is an intense vivid blue containing little to no matrix.

If you would like to see some great photos of Sleeping Beauty and other turquoise varieties, check these photos out I found on a site called rock-n-cabs.com.

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