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. The characteristics of sapphire from different regions are briefly described as follows:

Indian Kashmir sapphire. The color is blue in the cornflower, which is the indigo of the microstrip purple. The color has a large brightness and a bright color. The haze-like inclusion has a milky white reflective effect. Has always been hailed as the best in sapphire. The reason for this color sensation has not been conclusive. It may be caused by the fine particles such as rutile, or it may be caused by the scattering of light by some very small cracks and accompanying dissolved matter. The color is uneven and often forms. Clear blue and nearly colorless ribbons. However, because the mining area is located at the northwestern end of the Himalayas, it is more than 5,000 meters above sea level. It is covered with fog all year round and has not been produced in recent years.

Myanmar Mogok Sapphire. It is produced in the same mining area as ruby, and the other features are identical except for the color. Its inclusion body is as follows: 绢 rutile rutile inclusions, arranged in parallel with hexagonal cylinders, intersecting at 60 degrees and 120 degrees. If the vertical stell-like inclusion is cut, it can be six-shot or twelve-shot star after honing into a curved gemstone; the area of ​​the bubble in the void of the fingerprint-like liquid inclusion is small, about 30%; solid package Body, corundum, spinel, uranium pyrochlore, apatite, etc.

Sri Lankan sapphire. Same as a ruby ​​in a mining area, except for the different colors, the other characteristics are exactly the same. Its inclusions are as follows: 绢 filamentous inclusions, similar to Burmese sapphire, the difference is that the fibers are thin and long, can present six-shot starlight; liquid inclusions, in an amorphous layered fabric or fingerprint-like distribution; solid package Body, there are zircon, apatite, biotite and so on.

Thai sapphire. It has a black blue color and a light gray blue color. There are no filamentous inclusions in the crystal, but fingerprint-like liquid inclusions develop. The most characteristic is that there is a crack in the shape of a lotus leaf around the black solid inclusion body. The three groups of polycrystalline twin crystals developed, and the cracks split along the double crystal plane.