Cleiophane and Galena

Sample of euhedral tetrahedral Cleiophane with an adamantine lustre intertwined with subhedral cubic Galena. Sphalerite (ZnS) can be yellow, brown, red, green, black, white (rare) or pale grey (Cleiophane). Lustre is resinous, adamantine or submetallic and streak is light brown that is always lighter than the mineral colour. Hardness is 3 1/2 to 4 and cleavage is perfect in six directions. Sphalerite usually occurs as tetrahedral or dodecahedral with rounded faces but can also be cleavage masses, granular, compact or botryoidal. Galena (PbS) is a dark lead-grey mineral with a metallic lustre. Streak is dark lead-grey and hardness is 2 1/2. Cleavage is perfect in three directions at 90 degrees. Galena usually occurs as cubes or octahedrons but can also be massive, cleavage fragments, coarse or fine-grained and fibrous. *Smallman Collection