Reference work entry
This is a collective name for the seal stones produced in the Lishui area in Zhejiang Province. The name comes from the main production sites at Tushu Mountain, Fang Mountain and Fengmun Mountain in Shankou Town, Qingtian County. This stone is a Late Jurassic intermediate acidic volcanic rock (rhyolite and rhyolitic crystal tuff) subject to hydrothermal alteration. Its main component is pyrophyllite with small amounts of quartz, sericite, kaolinite, montmorillonite, sillimanite, epidote and diaspore. It is waxy with a vitreous lustre and is slightly transparent or translucent. It has a fine and dense texture, relatively soft and with a density of approximately 2.7 g/cm 3. This stone is resistant to water, moisture and fire and is rarely discoloured or deformed. The natural Qingtian stone can be divided into single colour, multiple colour, hard jade and red columnar types, which can be further subdivided into more than 100 varieties. The famous varieties are light-shade steatitic, fish...
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