Sphalerite and Galena

Five samples of coarse granular Galena entwined with yellowish euhedral tetrahedral/dodecahedral Sphalerite. Sphalerite (ZnS) can be yellow, brown, red, green, black, white (rare) or pale grey (Cleiophane). Lustre can be resinous, adamantine or submetallic and streak is light brown and is always lighter than the sample. 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. Lustre is metallic and streak is dark lead-grey. Hardness is 2 1/2 and cleavage is perfect in three directions at 90 degrees. Specific gravity is 7.4 to 7.6. Galena usually occurs as cubes or a combinations of cubes and octahedrons. Galena can also occur as dodecahedrons, massive, cleavage fragments, coarse to fine-grained or fibrous. .