(1) Yunnan Ruby
Yunnan ruby is produced in phlogopite marble in Ailaoshan old metamorphic rock distribution area in western Yunnan, but it is a secondary placer with mining value. The size of the ruby mined is 1 ~ 10 mm, and its color is rosy and red, rich and even. However, cleavage is developed, and inclusions and impurities are high. Most of them can only be used as globoidal gems, and rough stones with faceted gem quality are rare. Due to the scale of the deposit and other reasons, the output of rubies in Yunnan is very small, and it is impossible to maintain a stable market supply.
(2) Anhui Huoshan Ruby
Ruby in Huoshan, Anhui Province occurs in veins or lenses of biotite plagioclase in ultrabasic rocks or their marginal contact zones. Ruby's single crystal is generally small, with a diameter of 3-5 mm and a length of about 8 mm. It is hexagonal columnar, translucent, light purple to rose red and light in color. However, 5cm long ruby crystals were also found. Partially translucent-opaque rubies have good starlight. The area is dominated by primary minerals with a small scale, and few rubies have been put into the market at present.
③ Qinghai Ruby
Qinghai ruby is located in the west of Qinghai province, and it is produced in altered ultrabasic rocks invaded by metamorphic rocks. Ruby-containing corundum mica plagioclase is distributed in altered ultrabasic rocks in the form of lenses with different sizes. Ruby is deep rose red, usually with blue stripes or spots. The granularity is 5- 10mm, the length is 20-30mm, and the transparency is poor, which generally cannot reach the quality of faceted gemstones.
④ Ruby in Heilongjiang Province
Ruby is produced in the clay gravel layer in Long Mu, Heilongjiang Province, and its primary mineral is alkaline basalt. Ruby particle size 2-6mm, maximum 10mm, pink, good transparency. However, the scale of the deposit is very small and it has not yet become an economically significant producing area.
Ruby grading standards are mainly measured according to 1T and 4C: transparency, color, clarity, cut and carat weight. Ruby is one of the precious varieties in jewelry. Ruby is bright in color, and under the illumination of light source, it can reflect beautiful and moving six-ray starlight, commonly known as six lines, which is caused by the special crystal structure of ruby and its unique optical phenomenon. Ruby is transparent, translucent and opaque, and its colors are water red, pink, pigeon blood red and rose red. Because big gems are very rare, rubies with larger particles are generally fake. There are two kinds of fake rubies: the first is to pass the low-grade rubies off as rubies, and all fake rubies do not have the unique color of rubies. The second is artificial ruby. Artificial ruby is very similar to natural ruby in terms of specific gravity, hardness and color. Intuitively, artificial rubies have uniform texture, no natural impurities, even and positive color, often large particles and lack naturalness.