Friday, April 22, 2011

Turquoise is the Gemstone of the Week

Popular for thousands of years, Turquoise is the gemstone of the week this week. The popularity of this gemstone goes back to the ancient Egyptians and continues up through today. One thing that could account for the popularity is the fact that it is readily available and reasonably priced. Depending on the source, prices per carat can range from $1 to $50. Along with Zircon, it is the birthstone for December.

It is believed that the name, Turquoise, comes from the French word “pierre turquoise” meaning Turkish stone. That is a reference to the fact that Turquoise was brought to Europe from Persia by Turkish traders. For centuries, Persia (Iran) produced the most valuable Turquoise. Now, some Turquoise mined in the Southwestern U.S. compete easily in value. The term Persian Turquoise is used today to refer to stones that do not have the black or brown veining commonly found in U.S. stones.

Turquoise is an aluminum phosphate mineral. Bluer stones have a higher concentration of copper to give it it's coloring while greener stones have a higher concentration of iron or chromium. Since the soil makeup surrounding Turquoise deposits influences color, the location name is often included in the stone name. A perfect example of that is Sleeping Beauty Turquoise from the Sleeping Beauty Mine in Globe, Arizona.

Turquoise is a relatively soft stone-between 5 and 6 on the Moh scale, and is usually enhanced somehow. There are many ways of doing this. I have covered some of the more common processes and names of Turquoise on the market today.
     Foutz Enhanced Turquoise is the name for stones that have been treated by a process that impregnates and hardens the stone with vaporized quartz. This treatment is not detectable by normal testing methods. It is used on high to medium grade stones and will not work on low grade stones.

     Stabilized Turquoise has been treated with a plastic resin that allows lower grade stones to be suitable for using in jewelry.

     Wax treated turquoise works like stabilization and in the past, most Chinese Turquoise was treated this way. Today, most Turquoise from China is resin stablized since they have learned the process.

     Reconstituted Turquoise is mostly all man-made and should be labeled as imitation.

     Compressed nuggets are pieces of Turquoise that are bound with dye and resin. If you cut a piece of compressed Turquoise in half and look at the cross section, you can see the individual pieces of nuggets that were joined together.

     Chalk Turquoise is true, light blue, soft Turquoise that must be stablized to be used in jewelry. Today, there are some dyed stones that are passed off as Chalk Turquoise.

     Imitation and simulated Turquoise are stones that are made or dyed to look like Turquoise. Ceramic, polymer clay, glass and plastic are most often used for imitation Turquoise. Some of the more common stones that are dyed to create simulated Turquoise are Howlite, Magnesite and Dolomite.

     Do your research before you buy so you get what you pay for. Descriptive names are often used despite the chemical composition of the stone.

Turquoise today comes from several sources. In the U.S, Arizona, New Mexico and Nevada are the source. Other sources include, China, Mexico, Tibet, Iran, Peru, Africa, Austraila, Europe and Siberia.

It is believed the Turquoise has many powers. In ancient Persia, it was believe that if the stone changed colors, it was a warning of impending danger. It was often used to ward off the evil eye. Many cultures have held the belief that it is a good luck talisman. It's said that Turquoise enhances self confidence, and provides a sense of unity with one's self. Crystal healers recommend it for detoxifacation from alcohol, poison or radiation.

Here is a link to the Tantalizing Turquoise Collection I curated to go with this post.

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