China's Gemstone Resources (including Mineral Crystals) - Topaz (Yunnan)
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Topaz is a relatively common single crystal gemstone. Blue topaz is very common in the market. More precious varieties include imperial topaz. Topaz is also listed as the birthstone for November internationally.
In mineralogy, it is also called topaz. It is a complex of aluminum silicate, fluorine and hydroxide. The content ratio of F to OH is related to the mineralization conditions and directly affects the color, refractive index, density and other properties of topaz. It generally presents short columns and irregular particles. Today, let us learn about the topaz in Yunnan, my country.
PART 01
Distribution of Topaz in Yunnan
Yunnan's gem-grade topaz (topaz) is mainly distributed in Yuanyang, Fugong and Tengchong. According to relevant geological and mineral records, six mining sites have been discovered in the province, including a town in Tengchong, Baoshan City (gem types are topaz and beryl), three mining sites in Fugong, Nujiang Prefecture, and two mining sites in Honghe Prefecture.
PART 2
Gemstone Origin and Origin
Gem-grade topaz is mainly produced in the pegmatite caves in the southern section of the Ailao Mountain metamorphic belt. It has the characteristics of many points, wide areas and good quality, and is often symbiotic with gem-grade aquamarine and crystal. Topaz is also produced in the pegmatite in the northern section of the Gaoligong Mountain metamorphic belt.
Other pegmatite distribution areas have less output. The deposits are mainly pegmatite type, and the topaz associated with very few greisen-type tin deposits reaches gem grade but the particles are small. The main associated topaz deposits are aquamarine deposits in Yuanyang County and red beryl deposits in Yuanyang.
PART 3
Some deposit characteristics
01 Somewhere in Yuanyang
The pegmatite in this mining site is generally 5-80m long and 1-20m thick, mostly symmetrically differentiated, and produces minerals such as crystal, aquamarine, topaz, beryl, fluorite, tourmaline, etc. in the crystal cave. Topaz is generally light yellow to colorless, transparent, glassy, hardness 8, rhombic prism, complex rhombic single cone, growth lines on the crystal surface, small crystal parasitic, crystal size is generally 0.5-5cm, the largest is 5.2cmx4.4cm.
02 Somewhere in Fugong County
The rock vein is exposed at 80m and 2-5m thick, with slight alteration. Topaz and crystal are found in the crystal caves of the pegmatite vein. Topaz is 1-3cm. 2-5cm long. It is colorless and transparent, with intact crystals.
