Search Mineralpedia – A Mineral Photo Database and Identification Guide
Named after its commonly tetrahedral crystals, Tetrahedrite occurs “in hydrothermal veins or contact metamorphism deposits of low to medium temperature of formation.” One of the most common sulfosalts, Tetraherite is found in thousands of localities worldwide.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/tetrahedrite.pdf
Found only at its type locality at Mont Saint-Hilaire in Quebec, Canada, Thomasclarkite is named for the Canadian Professor Thomas Henry Clark of McGill University in Montreal who studied the geology of the Mont Saint-Hilaire region. Found in pegmatite dikes with associated intrusive alkaline-rich gabbro-syenite. Thomasclarkite is weakly radioactive.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/thomasclarkite-(Y).pdf