It seems that everywhere I look, people are wearing & talking about turquoise. When I used to think about turquoise, I remembered the inexpensive Native American silver creations that were hawked along old Route 66 in the 1960’s & 1970’s. Then there was a lot of it mass produced in China & passed off as Native American. The Native Americans were exploited (again) & many of those pieces were just sad junk. It has come a long way from that these days. Authentic, hand-crafted & signed Native American turquoise pieces now command substantial prices, commonly $300-$3000 & even higher for large necklaces.
Today turquoise is the hot new designer stone & is popular with celebrities on Red Carpets everywhere. While historically turquoise was almost always set in sterling silver, many designers now set it in 14-18 kt white or yellow gold.
The word “turquoise” is the old French word for “Turkey”, which is where the stone was first mined & put into general circulation in the Old World during the 14th century. Turquoise is mined mostly in the Middle East & the USA (Arizona, Colorado, Nevada & California) with smaller production in Australia, China & Chile. In general, it is a soft stone (Mohr’s scale 6) with an amorphous structure. It frequently has variable veins of matrix (the “mother” rock in which the turquoise is formed–usually a brown or black color; occasionally white) running through it.
Natural Turquoise is always some shade of light to medium green or blue. Despite what some sellers claim, these are the only naturally occurring colors.
There is a very pale blue variety called “White Buffalo” from the Dry Creek Mine in Nevada. Most “White Buffalo” turquoise offered for sale is actually natural howlite. Exotic colored turquoise (yellow or purple) are generally dyed howlite or synthetics.
The finest turquoise is generally accepted to come from the Sleeping Beauty mine in Arizona. It is readily distinguished by its lovely light to mid-sky or robin’s egg blue uniform color with little to no matrix visible. The mine is now closed, but a fair amount of Sleeping Beauty material is available for purchase from stocks owned by previous collectors. Prices are usually $30-50/ct. with large beads or cabochons commanding even higher prices. Other high grade turquoise runs $10-20/ct. “Jewelry Extravaganza with Mike” on the Gem Shopping Network is showing a lot of beautiful Sleeping Beauty turquoise very well set in gold with quality diamonds at reasonable prices.
Most natural turquoise (Sleeping Beauty being the notable exception) makes for some challenges in making jewelry due to its softness & the presence of matrix. The amount of treated or imitation turquoise on the market probably far exceeds that of natural material. Here is a list of terms to watch for so you will know what you are buying:
Enhanced turquoise is processed with vaporized quartz to make it harder. The quartz can be polished to a very high luster. The original material must be fairly hard to start with & this process is not easily detected without special testing.
Color Enhanced turquoise is dyed. High quality dying is usually permanent & won’t generally rub off. This material is more subject to fading than natural turquoise. Even natural turquoise will fade if subjected to strong light for long periods of time. Purple, yellow & intense kelly green turquoise are always dyed.
Stabilized turquoise is treated with a plastic resin to harden it. This allows lower-grade material to be used in jewelry, especially in “nuggets”. The plastic can be polished to a high shine. Waxes may be used to stabilize the turquoise in a similar manner. Wax is a surface treatment only. Stabilized turquoise usually costs $3-4/ct.
Reconstituted Turquoise consists of small stones, turquoise chalk powder (debris left over after cutting the rough) & dye mixed with a plastic binder. This material may also be referred to as “block“. It can be almost impossible to distinguish this from fake (synthetic) turquoise. The prices for reconstituted or fake turquoise should run around $1/ct or less.
Fake & Simulated Turquoise can include howlite, magnesite or dolomite that are dyed. White howlite is sometimes sold as “White Buffalo Turquoise” (see above). There are also glass, plastic, & ceramic or polymer clays that look very much like turquoise.
If you think that all these photos look a lot alike, you are very correct. It can be extremely hard to distinguish genuine, natural material from the rest. First consider the color–if it is totally uniform, be cautious–even Sleeping Beauty has a bit of color variation. If you look at the stone under high magnification, you should be able to see pores in natural stone that will be missing in plastic; pores in stabilized stone will be filled with clear material. Your best bet is, as usual, to purchase from a trusted source. An important piece should have a gem lab certification or at least documentation stating the origin of the stones. Up to seven different tests may be required to confirm if the material is genuine & determine its origin. If the price seems too good to be true, it probably is not natural. Now, there is nothing wrong with treated or faux turquoise–it can be very beautiful & make great jewelry–you just don’t want to be paying for natural when you are buying treated material.
You should treat your turquoise like your would your pearls: put on last to avoid hairspray, make-up or perfumes; store separately from harder stones to avoid scratches, but not in sealed air-tight containers; wipe only with a soft cloth to clean; avoid solvents, abrasive cleaners, salt or chlorinated water & bright sunlight. Untreated turquoise is porous, so it can absorb liquids & become stained.
I haven’t worked too much with turquoise yet, but I purchased some beautiful Chinese turquoise beads at Tucson last year. I have yet to finish their design as I am hand-casting some of the findings in bronze for it, but will post it as soon as it is done.