Every time we go through the PGG stock my eye falls on this lovely pendant; it’s a perfect size and a delicious colour, but aventurine, which is what this pendant is made of, is not my favourite blue coloured stone, and there are many to choose from. No, my favourite by far is turquoise – not the colour but the stone. (It is the only stone to have a colour named for it, by the way)
I’ve been familiar with turquoise for my whole magpie life; indeed I have turquoise dangly earrings from my youth, but I’ve never really paid attention to its amazingly varied colours or its long, long history. It turns out that turquoise is the oldest known stone to be used in jewellery. It was first mined in Persia but came to Europe through Turkey where the French word turquoise gave the stone its name. The Egyptians loved it; they mined it in the Sinai peninsular, and they used a lot of it because not only was it considered to be powerful protection but also it was associated with Hathor, goddess of the sky, of women and of love, and who was also known as The Lady of Turquoise. These powers of protection explain why so much was found buried in tombs, especially that of Tutankhamun whose burial mask was inlaid with turquoise, carnelian and lapis. When the Egyptians started making earthenware faience beads they were commonly glazed in turquoise blue because it was really their most revered colour.
A bit later in history turquoise was mentioned in the bible as being ‘…set in the breastplate of the High Priest’, and after that, on the other side of the world the Mayans had also discovered turquoise, and interestingly they worshipped it as much as the Egyptians had done, as did the Aztecs after them. They used it to embellish everything and were masters of mosaic using tiny tesserae which were made mostly of turquoise to which they added wood, other stone and even fish scales, and they carved it into amulets and other objects. The Aztecs so reckoned turquoise that Montezuma gave Cortez a piece of turquoise when he arrived because he thought Cortez was actually Quetzalcoati, the deity who contributed, basically, to the creation of mankind… Turquoise was also used as currency and traded right across the southern united states and Mexico long before, and even after, silver coinage was introduced to the Americas.
The Tibetan and Napalese people too have always revered turquoise believing it to be ‘heaven on earth’. Mined in the Himalayas, and generally but not always much greener than American turquoise, it has been part of the Tibetan culture for millennia; it’s considered as lucky to receive turquoise as it is to give it, and they it was who discovered that turquoise is so porous that it can absorb body oils and perfumes and that this often causes it to change colour.
Native North Americans have used turquoise in their jewellery forever; New Mexico used to be the prime source but now it’s Arizona. It seems that it wasn’t so much the stone as the colour that was so important, so glass or plastic or any other blue material would do, but then the tourists started coming and they wanted the real thing so the dealers in jewellery and other tourist delights had to up their game and source the real thing, and American mines continue to produce some of the best turquoise available, particularly the Sleeping Beauty mine in Globe, Arizona.
Two ways of producing turquoise when larger stones are needed but can’t be obtained is by stabilization or reconstitution. Turquoise is quite chalky and crumbly so it’s stabilized with plastic or waterglass and then compressed. It looks exactly like a turquoise stone but can be identified quite easily by close inspection with a refractometer. That’s not much help in the gift shop, though. Reconstitution is exactly what it sounds like; the little bits of turquoise are ground up and bonded together with resin to make large stones. Technically both these processes still end up with a gem made of turquoise but they shouldn’t be valued anywhere near the value of a pure piece of unadulterated turquoise. Just like every other gem, though, turquoise can be manufactured. Howlite, the most commonly used substitute, is a white stone with veining so when it’s dyed the right blue it does look exactly like turquoise. But there are tests that can be done, and if you have a piece of turquoise you’re not sure about you can put some acetone on a cotton bud and gently rub the ‘turquoise’ and see if any dye comes off. For better faking jobs the tests are more invasive and likely to damage the stone, but even scratching the back of a cabochon, for instance, can sometimes reveal the white stone underneath if it hasn’t been dyed too deeply.
Of course the most sought after and precious turquoises are the ones that are bright and clear without any inclusions because they’re so hard to come by now, but there is one exception to this; spider web turquoise is where the matrix runs through the stone in thin web like lines and while these too can be manufactured – what can’t nowadays? – a good spider web stone is obvious and very beautiful too.
A little known factoid about turquoise; It is almost impossible to tell where a turquoise stone came from because two very distantly located mines can produce stones of exactly the same chemical composition, and while American turquoise is generally bluer and Chinese and Tibetan greener, this is not always the case so can’t be used accurately for identification.
As a true magpie I don’t really care whether my pieces of turquoise are real or not, but I confess to generally preferring stones with matrix in them to the more valuable bright clear stones. Having said that, I’m very happy to have various qualities of turquoise in my collection because not only are they all lovely, but now I know how protected and lucky I really am!