bournonite crystals belong to the orthorhombic form of short columnar and plate, brittle, with metallic luster, often chenggang grey to dark grey. called the "wheel", which has the shape of a twin wheel.
the ore deposits are widely distributed in moderate and low temperature hydrothermal deposits, but not many. the main producing areas of china's wheel ore in the vicinity of hunan and inner mongolia, especially in the most famous yao yao xian.
the mineral crystal yaogangxian in ore deposits, but also often found with numerous skarn deposits, metallogenic conditions are excellent, so the development of mineral crystal perfection. the other association, an extraordinary as if done by the spirits as the acme of perfection, in different poses and with different expressions bournonite, is one of the best.
yao gang immortal wheel mine, known for its large crystal. at present, the largest single crystal, nearly 10 cm in diameter. it is generally recognized in the international mineral gemstone collectors, bournonite specimens of yaogangxian produced with bedrock, intact, crystal large, gentle color, are rare treasures.