Is a Calcium Iron silicate with formula CaFeSi2 O6 and hardness of 4-6.
Hedenbergite is the iron rich end member of the pyroxene group having a monoclinic crystal system. The mineral is extremely rarely found as a pure substance, and usually has to be synthesized in a lab. It was named in 1819 after M.A. Ludwig Hedenberg, who was the first to define hedenbergite as a mineral. Contact metamorphic rocks high in iron are the primary geologic setting for hedenbergite. This mineral is unique because it can be found in chondrites and skarns (calc–silicate metamorphic rocks). Since it is a member of the pyroxene family, there is a great deal of interest in its importance to general geologic processes.( from Wikipedia)
It comes from Brosso,Piemonte, Italy.
Weight: 5.27 ct.