Tetrahedrite, a member of the tetrahedrite group, is extremely rare at Mont-Saint-Hilaire.
Color ranges from steel-gray to black.
Luster is metallic.
Diaphaneity is opaque.
Crystal System is isometric; 43
Crystal Habits include fine-grained aggregates to 1mm and crude
aggregates of crystals.
Cleavage none apparent.
Fracture is uneven to subconchoidal.
Hardness is 3 – 4.5
Specific Gravity is approximately 4.8 g/cm
Streak is black.
Associated Minerals include aegirine, analcime, griceite, lovozerite,
molybdenite, pectolite, sodalite and villiaumite.
Distinguishing Features: Crystal habit.
Origin: Named in 1845 for the common tetrahedral form of its crystals.
MinRec 21:342 (1990), Dana 8:162-163 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE: