One of the rarest gems in the world, it is found in New Jersey in very small heavy included grains. This gem here instead, come from Poland. Several years ago an accident caused the breakage of zinc mining facilities and the conditions of heat, pressure and air were just right in order to form beautiful crystals of Zincite. Now they are getting rare and in the future this gem ( although is not completely natural) will be much more appreciate. The composition is zinc oxide, with traces of manganese and iron The hardness is 4 and it has a very nice luster. Big size!Today is became a rarity!.