Ore deposit type: Hydrothermal, polymetallic vein-type
Provenance: Montevecchio Mine (Sardinia, Italy)
Description: Vein characterized by bands of sphalerite (brown, evident cleavages) and quartz (white) in carbonate rock. The crustiform banding of the vein indicates changes in the physical-chemical conditions of the fluid, leading to precipitation of sphalerite first and then of quartz.