Sapphire is as expensive as ruby. If the color, clarity, and cutting are good, the price is very high. A small one often costs tens of thousands of yuan. But there are a lot of counterfeit sapphires on the market, so be cautious and buy a high quality sapphire for a small amount of money.
The most common is sapphire on the market. In fact, it is easier to identify glass. The glass is pressed out at a high temperature and shrinks naturally after cooling, and the plane is recessed inward. This sag phenomenon is not easy to find with the naked eye. It must be magnified by a magnifying glass. When using a magnifying glass, it cannot be linearly focused. It should be obliquely focused, and it is easy to find concave, concave, usually glass. The polishing of the gemstone usually achieves a very flat effect. Another method of identification is that there are many types of inclusions in the glass, the most common being bubbles, and the stones are free of bubbles. The bubbles in the glass can be found by observing with a magnifying glass of 10 times.
There is also a synthetic sapphire that acts as a sapphire. The identification method is to look at the texture first, whether the texture of the texture is naturally crystallized, and the natural crystallization is often messy and disordered, so it is usually genuine. The synthetic sapphire, the crystal is often very orderly. Of course, many synthetic sapphires are clean and flawless, which is usually fake. Because natural gemstones are always somewhat foreign, there is almost no cleanliness. This synthetic sapphire is often glaring in color, very radiant, and has no deep sense of natural color. The natural gemstones are of high purity and are not glaring, and the brilliance is naturally emitted from the inside out.
Ruby and sapphire are commonly referred to as red and blue gems. In fact, real rubies and sapphire are gem-quality corundums (corundum is a mineral name). The hardness of red and sapphire is The minerals of nature are second only to diamonds. Their chemical composition is alumina (Al2O3). It is colorless when pure. It is red when it contains 0.9%-4% of chromium. It is blue when it contains iron and titanium. The shape is three-way. Crystalline, the crystal form in nature is often columnar (slightly thin at both ends, slightly thick in the middle) or plate-shaped hexagon, the appearance is more like barrel; color is mainly colorless, red and blue, ruby ​​is mainly deep Fuchsia or orange-red, sapphire is mainly blue or blue-green, and other colors are green, yellow, pink, brown, etc.; hardness is 9; relative density is 3.99-4.0; due to common polycrystalline twin crystal, contact twin crystal, There will be cracking; the whole is transparent to translucent, the gloss shows glass luster to yam diamond, ruby ​​has obvious red fluorescence under UV light, most of sapphire is non-fluorescent; usually red and sapphire can reach 1.762 -1.778, for red and sapphire containing three sets of aligned fibrous inclusions, a curved facet cut can produce a starlight effect.
The red and sapphire natural products and synthetic products are very different in appearance. First, the growth lines in the gemstones are observed. The flame melting method is mostly curved, while the natural crystals form straight fold lines. Again, observing the inclusions in the gemstone, the flux method synthetic gemstone often contains the melting point of the melting point and the coloring flux residue, which is a "worm-like" under a 20-fold magnifying glass; sometimes there are circular bubbles and Tiny bubbles, sometimes visible hexagonal or triangular platinum pieces that fall off the enamel. The inclusions in natural gemstones are mostly fine rutile crystals or fingerprint-like gas-liquid inclusions; small cracks are also common. The last thing is to observe its color. The color of the synthetic product is too bright and very uniform. It looks a bit dull and glaring, while the natural color is relatively soft.
The difference between sapphire and similar blue gems and synthetic blue gems. Similar blue gemstones include blue spinel, blue tourmaline, blue zircon, blue cone, kyanite, cordierite, and the like. Synthetic gemstones similar to this include synthetic sapphire, synthetic spinel, and cobalt-containing blue glass.
Blue spinel: uniform color, micro-striped gray, crystal octahedron, homogeneous body, no dichroism.
Blue tourmaline: the color is greenish blue, the crystal is a complex triangular column, the hardness, density, and refractive index are lower than sapphire, the dichroism is very obvious, and the birefringence is large.
Blue zircon: Heat treated zircon with bright color, strong dispersion and high birefringence.
Synthetic sapphire: uniform color, clean, rare inclusions, round bubbles, homogeneous body.
Evaluation and purchase of sapphire.
The evaluation and purchase factors of sapphire are color, weight, transparency and clarity. The biggest feature of sapphire is that the color is not uniform, the polycrystalline twin crystal is not developed, and the dichroism is strong.
The sapphire produced in Myanmar is bright blue (including titanium coloration), which can produce six or twelve stars due to inclusions.
Indian Kashmir sapphire, blue cornflower, is a micro-purple purple indigo, bright color, is a high quality sapphire.
Sapphire produced in Sri Lanka, Thailand, China and Australia also has its own characteristics.
Sapphire is brittle and should be worn and bumped when worn.
The biggest feature of sapphire is that the color is uneven, and the flat ribbons and growth lines with different depths can be seen in parallel hexagonal cylinders. Polycrystalline twin crystal development, common blinds double crystal grain. The cracking is split along the double crystal plane. In addition to the above common features, sapphire in different regions of the world is also characterized by different origins. There are not many world sapphire producing areas, mainly Myanmar, Sri Lanka, Thailand, Australia, China, etc., but in terms of gem quality, Myanmar and Sri Lanka have the best quality.
Depending on the geological origin, it can be divided into two categories: one is sapphire produced in Myanmar, Sri Lanka and Kashmir, India. The other category is sapphire from Australia, Thailand and China. The sapphire of Myanmar and other real estates, due to the coloration of titanium, is bright blue, containing silky rutile and fingerprint-like liquid inclusions. The silky rutile inclusions can produce six or twelve starlights and are of high quality gemstones. The sapphire produced in Australia, Thailand and China contains more iron and is colored by iron. Therefore, the color of the gemstone is very dark, and the reflection effect of the faceted gemstone is not very good. Generally, it needs to be heated and processed to be used.
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