Formula: | ZnS | Click to see a larger image |
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Crystal: | Isometric-tetrahedral | |||
Hardness: | 3.5-4 | |||
Spec. Gr.: | 3.9-4.05 | |||
Streak: | Brownish | |||
Cleavage: | Perfect in 6 directions | |||
Location: | Trepca, Serbia |
Marmatite is chemically a ferroan sphalerite. It contains, in addition to zinc sulfide, up to twenty percent of iron. It appears to be an uncommon mineral, but that may be because it is brilliant black, much like brilliant black sphalerite, and for the most part may remain unrecognized. Marmatite is seldom mentioned in the literature. In general it appears to be sphalerite, varying only in its composition. The Stari Trg mine at Trepca, Serbia (formerly Yugoslavia) has produced some of the better crystals, which are particularly showy when combined with snow-white quartz crystals. |
Bibliography: Mineralogical Record, Stari Trg Mine, Trepca, V19, pg. 44 and 124. |
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