Wehrlite

Even within a single massif the igneous suite may be highly variable and range in character from quartz-normative tholeiitic to under-saturated alkaline. Rock types include wehrlite, olivine pyroxenite and hornblendite; teschenite, eucrite, and olivine, hypersthene, and hornblende gabbros; diorite, trondhjemite, alkaline syenite, and granophyre; augite, hypersthene, and oligoclase basalts and dolerites; variolite and camptonite.

While tetradymite has been recorded in shallow settings (e.g., Boulder County belt), this mineral along with other bismuth tellurides like wehrlite, tellurbismuth, and so forth (see Thompson, 1949) seem to be most common in mesothermal and even more intense settings.