Is a Hydrated Calcium Aluminium Iron Magnesium Silicate Carbonate Hydroxide with formula (Ca4(Al,Fe,Mg)10Si12O35(OH)12CO3·12 H2O) and hardness of 3.
It is found as tin incrustation over rocks,rarely is thick enough to be cut,and always porous.
It comes from Caserras del Castillo,Estopinàn del Castillo,Huesca,Aragòn,Spain
Size: 10x7.7x5.5 mm.
Weight: 2.78 ct.