Geological classification

How to distinguish real fluorite from a fake?

In the second part we will look at rose quartz, rauchtopaz, morion and fluorite . Pink quartz – Natural opaque rose quartz usually has internal defects, microcracks, zones of varying opacity and is practically never perfect. For example, if you take a polished ball of this mineral, one part may be white and the other pink. The presence of these signs indicates a natural origin. Its crystalline masses are riddled with cracks, translucent or almost transparent, and, as a rule, slightly cloudy. The color is given by impurities of titanium and manganese. When polished into a cabochon, tiny rutile needles, cracks and voids create a six-pointed star or a cat’s eye effect. Pure transparent varieties are worthy of cutting. Imitations of rose quartz are often made using glass that has been treated appropriately to reproduce the veining and inclusions characteristic of real stones. Rose quartz is also characterized by coolness and hardness of 7 on the Mohs scale, i.e. it also scratches the glass. Rose quartz often fades over time, except Brazilian rose quartz, which does not lose color even after prolonged exposure to sunlight. (It is better to store rose quartz in a dark place.) Imitation rose quartz is often sold on trays – a homogeneous opaque mass that looks like plastic, is bright pink in color, has rounded edges and weighs significantly less than the real thing. Also, transparent glass of various shades of pink can be sold as rose quartz, but natural transparent rose quartz is rare; it is then cut into jewelry cuts and such a stone is expensive. Most imitations and fakes today are made from glass of various qualities with various coloring additives (Savrovsky stones, glass rhinestones, black and golden aventurine, colored cat’s eye, milky moonstone, green chrysoberyl, opal glass, etc.). Even rauchtopazes (smoky quartz), morions (black quartz) and agates, the reserves of which are sufficient in nature, began to be counterfeited with glass. Smoky quartz – rauchtopaz (German rauch – “smoke”), a type of crystalline smoky quartz from gray to dark gray and brown (but not black), necessarily a transparent mineral. It may even be valued on a par with topaz, but contrary to popular belief, rauchtopaz has nothing to do with topaz. In fact, rauchtopaz is an outdated name that remains mostly in everyday use. Along with rock crystal, citrine and amethyst, rauchtopaz is the most valuable variety of quartz. Its golden-brown crystals with inclusions of rutile, which create the effect of star rays scattering in all directions, are especially beautiful. In nature, giant smoky quartz crystals weighing up to several tons are sometimes found. Rauchtopaz is not as popular as amethyst and is unlikely to be painted or irradiated en masse. The only way to protect yourself here is not to buy rauchtopaz from Brazil and the USA. There is still enough of it in the CIS. By the way, rauchtopaz is the national stone of Scotland; it was highly respected by the Druids. Morion – black and dark brown almost opaque quartz (silicon oxide), only thin sections of the morion are visible. There is no synthetic morion yet (its natural reserves are sufficient). Morion entering the Russian market, unfortunately, in most cases is artificially irradiated. Fortunately, unlike citrine, there is a technique that can reveal a refined stone. Check with the seller about the origin of the stone: if this is the USA (Arkansas, New Mexico), then you can turn around and leave. The thing is that deposits of transparent quartz with the makings of a morion color in the crystal lattice were discovered in Arkansas, which for some reason did not appear over a very long period (hundreds of millions of years), which suggests that the morion becomes black not from the natural radiation of stars, but from a radiation source in the rock. This quartz is irradiated and sold as morion. The distinctive features of irradiated morion (besides being cheap) are the following (most likely, this may be true for artificially irradiated smoky quartz): Irradiated morion crystals are white or gray at the base (or close to the parent rock if it is a druse). If, along with this sign, there is a strong shine on the surface of the crystals, and they are not completely translucent, then this is definitely irradiated transparent quartz. Natural morion may also not be transparent and be glossy (usually partially), but it is black (dark brown) “from head to toe.” In the jewelry industry, annealed morions are used for cutting, which, during the annealing process, acquire a wine-yellow and yellow color and turn into citrines. Fluorite is a transparent or translucent stone with a glassy luster, of various colors: colorless, blue, pink, yellow, green, violet (almost black). Unevenness and varying intensity of color are often noted, and banded and spotted varieties are found. Pure fluorite is colorless and water-transparent, with a glassy luster, but it is usually green, violet, yellow and other colors, which are caused by impurities or may be the result of radioactive effects (yellow color). Dark purple fluorites contain increased amounts of strontium, and green varieties contain some samarium. Rare earth elements and some heavy metals, as well as excess calcium ions, give it different colors. True to its name, fluorite fluoresces strongly (purple under ultraviolet light), it is too soft for a gemstone, only 4 on the Mohs scale, and therefore will always have abrasions or scratches on the edges. So if you suspect that the fluorite is colored, scratch it with a piece of glass (it won’t be scratched with a paper clip). By weight, fluorite seems heavy because it is a fairly dense mineral. Its colorless crystals are a material for the manufacture of high-quality lenses. However, it is difficult to find deposits of optical fluorite, and therefore now it, like quartz, is synthesized. But this is done by large companies that have their own laboratories, so you don’t have to be afraid of synthesized transparent fluorite, but it’s better to buy it in druses or crystals (but they are inconspicuous and can be expensive). Large deposits of fluorites have been discovered in Mongolia. In Russia, this mineral is mined in the Chita region (Kalanguy) and in Primorye (Dalnegorsk). There is also inexpensive green fluorite on the market from China. It is not surprising that deep green varieties of fluorite have long been sold as emeralds, red, crimson and pink as rubies, yellow and orange as topazes, blue-violet as sapphires, and lilac and purple as amethysts. Only a specialist can guess that crystals that are so different in appearance are essentially the same mineral. Thus, in the Special Storeroom of the Hermitage there is a bowl, a cup and a jug that belonged to Tsar Alexei Mikhailovich, which were considered to be carved from purple “amethyst” quartz, but turned out to be fluorite. Of all the natural emerald-like stones, only fluorite poses a problem. This mineral can only pass for a low-quality emerald, but when examined under a magnifying glass, you can often notice the famous “three stages” inclusions characteristic of Colombian stones. It also appears red under a color filter, as do most emeralds, natural and synthetic. However, checking with a refractometer will put everything in its place. Even if you have never seen fluorite, you are probably familiar with the phenomenon of fluorescence – the ability of an object to glow. This phenomenon was named after a natural jewelry stone that has such an amazing property. Let’s find out how to distinguish fluorite from a fake.

Mineral Features

Fluorite is a brittle and not very hard fluorspar, which in nature forms in the form of crystals of various colors. It cannot be called rare, since it is found in many countries, but at the same time it is unique. So, the chemical formula of this nugget includes fluorine, and this is a rare property for minerals, and it also has the unusual ability to glow in ultraviolet rays (photoluminescence property), and when heated, the gem sparkles brightly (thermoluminescence). Fluorite is the most luminous nugget in the world.

What does fluorite look like?

By itself, it has no color, but defects in the crystal lattice give it a particular shade. It can be almost anything, even rainbow. Moreover, one crystal can have different shades and beautiful color transitions, for example, from green to purple. You can recognize it by its structure – it is absolutely transparent, and by its cold glassy sheen.

The mineral is used not only in jewelry, but also in metallurgy, various industries, and for the manufacture of night vision lenses

Jewelry quality is approx. 5% of the mass of mined nuggets.

How to distinguish from fakes

Fluorite has always been confused with other nuggets – it is a master of camouflage, so it was passed off as both a precious and semi-precious stone. But now this gem is often counterfeited, passing it off as glass or even plastic. Sometimes buyers are offered supposedly synthesized fluorite, but this is also a fake, since this gem is not grown in laboratories. A fake can be identified by color. Thus, blue-green samples are most often mined in deposits, but transparent pink-red or rainbow ones are considered very rare. The same goes for fluorite hairs, a speckled specimen that is highly prized by collectors. It is difficult to find such stones on sale, especially if they are suspiciously cheap. The natural mineral has good density, so it cannot be as light as plastic or glass. In addition, it is very fragile and soft (which is why it is not considered a precious stone), so its surface will in any case be scratches, abrasions and chips. If you suspect that the stone can be scratched by glass, a scratch will certainly appear on the natural sample.

Please note that you should not test for softness, for example, with a paper clip, since it will definitely not scratch it.

Be sure to hold the gem in your hand. If it is colored glass or plastic, it will begin to heat up quickly, while natural fluorite will feel cool longer. Finally, the nugget must exhibit the most important property, that is glow in ultraviolet rays. Moreover, no equipment or heating is required for testing: just take the stone out into the sun and after some time in direct sunlight it will shine. Fluorite is a soft and brittle fluorspar with the amazing property of glowing in ultraviolet rays. Even though it is found in many countries, it is often counterfeited. You can distinguish a gem from colored glass or plastic by its density, the presence of defects, and a pronounced glow.

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