Wednesday, June 30, 2010

What is Turquoise?

By. Alan Eby

Hello Friends,

I'd like to take some time and talk about one of my favorite things, Turquoise!

Turquoise is one of the Earth's oldest known gemstones. It was used by the Egyptians and is mentioned in the Bible quite a few times. Turquoise is a blue/green copper mineral its measured between 5 and 6 on the MOHs hardness scale. This beautiful stone found current popularity in the 70's and 80's due to its use in Native American jewelry being made in Arizona and New Mexico.

For many reasons, less pricey alternatives to natural turquoise have been developed. Along with these, there have also been a few ways to treat poorer quality turquoise to make it usable. I hope that this column will be helpful for those of you who use turquoise in your art, and all those interested in this beautiful and ancient stone.

Very little of turquoise is actually usable, because of poor color or because weakness and/or fractures. This makes natural untreated stone very valuable. Due to these issues and turquoise’s increasing popularity in the 70's and 80's, treatments were developed so more of the stone could be used.

Natural Turquoise, is the turquoise that has a nice color and will hold up during cutting and polishing. Sometimes to protect the polish and luster of natural turquoise, the stone is waxed but other than that Natural should be just that. Natural turquoise will change color over time or in certain conditions.

Stabilization is a process in which weak stone is treated with a mixture of epoxy and resin. This takes an otherwise unusable stone and increases its ability to be cut and polished. A side effect of the stabilization is that the color of the stone will not change.

Enhanced turquoise is a common term for turquoise treated with the Zachery process. The Zachary process is the invention of an employee of R.H. & Co. named James E. Zachary. This process is a secret owned and copyrighted by the company. So while I cannot tell you exactly what they do, I can tell you that it darkens and strengthens the stone. Also the like with the stabilized turquoise the color won't change in enhanced turquoise.

These process are there to increase the value and usability of otherwise worthless rocks. In this economy many are looking for inexpensive alternatives to rather pricey items. One of these is turquoise jewelry. Magnacite is quickly becoming the most popular substitute for turquoise. Magnacite is naturally a white and brown, chalky stone, that takes dyes and a polish rather well. Its found in a wide variety of colors making it not just an alternative to turquoise but many other stones as well.

Reconstituted Turquoise, is stone flakes and chips compressed together with epoxy and sometimes dyed. Its generally a strong and easy to cut composition, it can be useful for carving as well.

Block is plastic mixed with some natural materials and dyed to imitate a large selection of semi-precious stones. Block usually comes in square pieces, and is very smooth. When its being sold its labeled along with the name of the stone its imitating. (example. Block Turquoise, Block Lapis, etc.)

These alternatives are not meant to fool the consumer but to be an economical alternative to a more expensive stone. Sometimes these imitations are sold as natural, sometimes because of a mistake, sometimes it can be dishonest.

I hope this column has been helpful to both artists and jewelry enthusiasts.

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