is a molybdenum disulfide with formula MoS2 and hardness of 1-1.5.
Similar to graphite with a metallic luster; it is made by layers of molybdenum atoms between sheets of sulfur atoms, the result is a greasy slippage as wells as cleavage planes.
Hence the cutting is a real challenge, you will not find anywhere in the market facet gems!
It comes from Mina Jardinera No. 1 ,Inca de Oro,II Region,Atacama Desert,Chile.
Size: 8.8x7.4x6.5 mm.
Weight: 4.83 ct.