Mineralpedia Details for Tennantite
Named to honor Professor Smithson Tennant, a chemist of Oxford University at Oxford, England. Tennantite occurs in deposits metamorphosed by contact metamorphism as well as in hydrothermal veins. Found in over a thousand localities and related to tetrahedrite, but is more rare than tetrahedrite.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/tennantite.pdf
Tennantite from Leonard mine, Butte dist., Silver Bow Co., Montana, United States
2mm tetrahedras which are rimmed with perhaps a different mineral, possibly Chalcocite. The cores are a brilliant silver, while the rims are a brassy chalcocite color and the outer rim is a dull, pitted, black or dark grey. There are numerous minute clusters of Quartz about the matrix.
Tennantite from Dzhezkazgan mine, Karagandy, Kazakhstan
Crystal group with individual crystals to 6mm.
Tennantite from Cornwall, England
An interesting specimen with hundreds of well developed crystals to 1mm on sulfide matrix. The cavity on which the crystals have formed is large and is 6x5cm across and composed mostly of Chalcocite. The rest of the matrix is sulfide, probably Chalcopyrite There is also some vugs on the backside.
Tennantite from Tsumeb mine, Tsumeb, Namibia
Two good Tennantite crystals - 1.9 and 1.4cm.