Halotrichite, a member of the halotrichite group, is extremely rare at Mont Saint-Hilaire.
Color is usually white.
Luster is silky.
Diaphaneity is transparent.
Crystal System is monoclinic; P2/m.
Crystal Habits include very fine bent silky fibers to 2mm.
Cleavage not observed.
Fracture is not apparent.
Hardness is 1.5
Specific Gravity is approximately 1.95 g/cm3.
Streak is white.
Associated Minerals include albite, pyrite, siderite and sphalerite.
Distinguishing Features: Crystal habit.
Origin: Named in 1839 from the Latin halotrichum, hair salt,
alluding to its silky hairlike habit.
MinRec 21:313-314 (1990), Dana 8:617 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE: