Numerous crystals of this rare nickel species, on a museum-sized display plate! 2 to 5mm, silvery white siegenite crystals cover the face of this cabinet piece whose matrix is composed dominantly of silicified dolomite. Siegenite is an uncommon cobalt nickel sulfide and is an extremely rare mineral from Missouri's Viburnum Trend. These crystals and clusters on this piece are huge for the species! An exceptional specimen most likely collected during mining efforts at the Buick mine in the 1980's.