The word "stabilise" in my turquoise blog of a couple of days ago, seems to have stirred up emotions in some of you. Okay let's get this straight. Just because turquoise is stabilised does not make it fake. Of course there is a lot of fake turquoise on the market, but that doesn't need to be stabilise. Because it's fake. 95%-98% of commercial gem grade turquoise on the market is stabilised. This is done in a number of ways, for a number of reasons.
Turquoise is a relatively soft, porous stone. The porous nature of turquoise makes it very sensitive to light, and changes in temperature and humidity. A piece of unstabilised turquoise will change colour just by being worn, in a relatively short period of time. Stabilising also slightly hardens the gemstone, making it easier to cut into cabochons. The process of stabilising turquoise has traditionally been achieved by using waxy resins. In more recent times the process has becoming more sophisticated, involving high pressure, sodium silicate solution, and many months to complete.
for 5,000 years or more turquoise has been mind and valued. Evidence of this is been found in the tombs of the Pharaohs. Where there is value, there is copying. Lately there's been quite a lot of fake turquoise turning up on eBay in the form of nuggets both large and small. (I've provided a link to an interesting article on this). As most fake turquoise is constructed using some form of it epoxy resin, I generally test by using a red hot needle. If the needle sticks and you can smell plastic, it's definitely fake. There are other types of fake turquoise such as dyed howlite where this test won't be effective. In that instance, you need to know what dyed howlite looks and feels.
The majority of turquoise in the global gemstone market is from United States and Mexico. Mine's such as Kingman, Sleeping Beauty, Campo Frio have produced beautiful turquoise for many years. But 95% of the turquoise that I sell come from Persia, or Iran. I prefer it because its easier to find with very little or no matrix, and the fact that it's always slightly harder than it's American and Chinese counterparts. Making for much nicer cabochons. In my opinion.
For anyone reading this blog who is not into gemstones, well done for getting this far. And I can only apologise for the blog being so geeky.