Geological classification

What is the name of a stone that looks like turquoise?

When purchasing products with turquoise, keep in mind that these stones can be natural or artificial; they have many differences that are not always noticeable to a non-professional. When purchasing products with turquoise, keep in mind that these stones can be natural or artificial; they have many differences that are not always noticeable to a non-professional. Some imitations of this mineral are highly valued, such as howlite, which is very similar to turquoise and is often used in jewelry.

Place of Birth

Nowadays, the mines of Iran remain one of the most ancient deposits of turquoise in the world. Previously, this country was called Persia. Turquoise was mined here back in the 50rd millennium BC. e. Iranian turquoise has the most intense bluish blue color. The most famous mines are the Nishapur mines. They are located 60-XNUMX km northeast of the Iranian city of Nishapur. In the old days, it was located right on the main caravan route between East and West. It is from here that the best examples of turquoise still end up on the world gemstone markets. The Nishapur mines are not the only ones in Iran. Hundreds of mines continue to operate in this country, where they extract high-quality turquoise, which is unofficially considered the national talisman stone of Iran. Turquoise is mined in Uzbekistan, Kazakhstan and Tajikistan. One of the famous deposits in Tajikistan is called Biryuzakan. Here, high-quality turquoise is mined on the southern slope of the Kuraminsky ridge at an altitude of 1400-1450 m above sea level. Afghanistan can boast of excellent examples of turquoise. The increase in its production in this country is hampered only by the turbulent political situation in the region. Recently, turquoise began to arrive on world markets from Mongolia, where it is mined in the vicinity of the city of Erdenet. Other countries where turquoise is mined are Armenia, Israel, Ethiopia, Australia and China. If you have ever vacationed in Egypt, you have probably come across items decorated with turquoise in local jewelry shops. She is most likely local, Egyptian. Or rather, Sinai. In the southwestern part of the peninsula there are some of the oldest mines in the world – the Jeb Hamd, Sarabit al Kadim and Wadi Maga-re mines. From here, blue azurite and chrysocolla, green copper and, of course, turquoise were brought to the heart of Ancient Egypt. After the decline of the great Egyptian civilization, the ancient mines in Sinai were abandoned for a long time, but nowadays gem mining is being carried out again In the New World, large turquoise mines exist in New Mexico within the Chaco National Historical Park. The most famous American deposit in Arizona is Bizbee. The city of Tucson annually hosts mineralogical exhibitions, where, among other wonders, you can see magnificent specimens of turquoise. Other famous American deposits of turquoise include Lone Mountain (Nevada), Turkoz Hill (New Mexico). In the Mojave Desert, deposits such as the Inyo Mountains and Baker are known. The largest turquoise deposit in Nevada is called the Royal Blue Mine. In Russia, samples of turquoise are found on the territory of the Komi Republic.

Types of imitations

Chrysocolla can be mistaken for turquoise. The mineral howlite also resembles turquoise. It is easy to paint and therefore often acts as a substitute for turquoise. The imitation is so accurate that sometimes unscrupulous dealers deliberately pass off colored howlite as real turquoise. Emerald turquoise is often called the mineral faustite. Its structure surprisingly matches that of turquoise. The only difference is that instead of ferric iron, it contains zinc atoms. It is no coincidence that faustite is considered a zinc analogue of turquoise. California turquoise is the name given to samples of the mineral variscite, which are mined in the US states of Utah and Nevada. The apple-green or bluish color of variscite, similar to turquoise, is given by impurities of iron and chlorine ions. In the middle of the 20th century. An imitation of turquoise appeared – “Neolithic” – a mixture of beyerite and copper phosphate. Dark veins were created due to the admixture of amorphous iron compounds. Both imitations can be distinguished from natural stone using hydrochloric acid, which gives the fakes a bright greenish-yellow color. The easiest way to distinguish from natural stone are samples obtained by pressing waste natural turquoise. Sellers in Egypt will ardently convince you that this is the most natural turquoise, although even a non-specialist will see that it consists of many small fragments literally welded together. Vienna turquoise is an imitation of turquoise, which began to be produced in the 19th century. by pressing precipitated phosphate tinted with copper oleate. Howlite is a calcium borosilicate named after Canadian geologist Henry Gove. Howlite is easy to paint and therefore often acts as a substitute for turquoise. Greenish turquoise is considered “old” and its color is caused by iron compounds. Sky blue turquoise is considered “young” and its color is caused by copper ions. Odontolite, also known as “toothstone”, “turquoise bone”, “bone turquoise” are fossil bones, teeth and tusks, in which some of the organic and mineral substances are replaced by compounds containing phosphates and iron ions. Externally, odontolite resembles turquoise. These photos show what a turquoise stone and its varieties look like: Turquoise is not the most expensive stone, but in terms of the number of fakes these days it shares an honorable first place with rubies, sapphires and emeralds. The literature writes about the prevalence of such types of counterfeiting as: 1) Dyed mineral howlite. 2) Something “stabilized”, “restored”, “pressed” – not directly related to turquoise. To be honest, stabilized turquoise can only be called ordinary real natural turquoise, coated during the processing of cabochons or beads with an additional protective layer of stabilizing polymers – such turquoise is less “capricious” in products and does not deteriorate if any caustic substance suddenly gets on it. In general, stabilized turquoise was originally a term for normal finishing. But under this “brand” they can offer anything. As well as under the names “restored” and “pressed”. Turquoise is actually NOT restored or pressed in any way, these are delicate trade names for imitations. 3) You also come across many different imitations made from completely different materials – ceramics, plastic, fimo, enamel. In general, there are countless ways to fake turquoise. But for some reason, there is little information about what is actually the most common method of counterfeiting turquoise on the stone market today – the painted mineral magnesite. Magnesite is a very common mineral and chemical composition in nature. Magnesium oxide (MgO) 47,6%, carbon dioxide (CO2) 52,4%. Impurities of iron, manganese, calcium. Compared to the well-known howlite, magnesite is an even cheaper material and is even less suitable for jewelry use. The largest source of supplies of colored magnesite under the guise of “turquoise” is in India. Sometimes such stones are even accompanied by certificates stating that they are turquoise. To be convincing and in order to reduce labor costs for this waste material, it is often ground somehow, leaving traces of shellac on it. A not very experienced buyer perceives such a semi-finished product as the natural “raw material” of real turquoise. Wow, how cheap and convenient! – just finish polishing, finishing. And sometimes, even in the process of polishing such imitations, they do not notice what they are actually dealing with. How to check turquoise? Our traditional answer to this is to take it to a gemologist. A gemologist sees through a microscope the characteristic features of the structure of a particular mineral; this cannot be explained in a nutshell. Counterfeits can be very similar and reliable; most jewelers, for example, cannot distinguish them. As a result, they spread en masse. Today, in most cases, finished “author’s” jewelry contains colored magnesite or howlite. What signs should you look out for: 1) The hardness of turquoise is 5-6, the hardness of magnesite is 3,5-4,5, howlite is 3,5. The difference is palpable. Turquoise is a more monolithic stone and takes polish much better. Magnesite has a more matte, dull surface and a tendency to crumble. It’s getting ridiculous – people are so used to seeing dull magnesite or howlite in jewelry that doesn’t accept polishing, that when looking at perfectly polished selected turquoise (with an even color, without a matrix) they exclaim – it’s some kind of plastic! How can you test hardness? Buy special gemological “pencils” for determining hardness, a useful and easy-to-use item. 2) Often the paint on magnesite fades. The first test is to soak in water overnight, or scrub under water with a toothbrush and a mild detergent (such as dish soap). Turquoise foam began to appear, the water became colored – there was no hope. paint. In general, this paint is very harmful. In most cases, the composition is something close to copper sulfate (those who have experience working with this substance around the house and garden know to what extent this is a toxic composition). So, painted magnesite is not even suitable as jewelry, have mercy on yourself. However, if the paint does not fade, this is not a guarantee that there was no staining. To prevent dye migration, the cabochon can be additionally impregnated with wax, stabilizer or varnish. In general, there are a lot of tricks. We would like to emphasize that such tests at home cannot CONFIRM turquoise, but can only EXCLUDE an obvious fake. To be on the safe side, you should always have your stones checked by a gemologist.

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