Tetrahedrite
(Cu,Fe)₁₂Sb₄S₁₃

     Tetrahedrite, a member of the tetrahedrite group, is extremely rare at Mont-Saint-Hilaire.

PHYSICAL CHARACTERISTICS:

Color ranges from steel-gray to black.
Luster is metallic.
Diaphaneity is opaque.
Crystal System is isometric; I43m.
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/cm³.
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.

CLASSIFICATION:

REFERENCES:
MinRec 21:342 (1990), Dana 8:162-163 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

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