Cordierite
(Mg,Fe²⁺)₂Al₃(AlSi₅O₁₈) · H₂O

     Cordierite is rare at MSH.

PHYSICAL CHARACTERISTICS:

Color is usually white or pale gray.
Luster is vitreous to greasy.
Diaphaneity is transparent to translucent.
Crystal System is orthorhombic; Cccm.
Crystal Habits include small embedded grains.
Cleavage {100} is moderate, while {001} and {010} are poor.
Fracture is conchoidal to uneven.
Hardness is 7.
Specific Gravity is approximately 2.6 g/cm³.
Streak is white.
Associated Minerals include (??).
Distinguishing Features: Crystal habits.
Origin: Named in 1813 after Pierre Louis Antoine Cordier (1777-1862),
   French geologist who described the mineral.

CLASSIFICATION:

REFERENCES:
Dana 8:1251-1253 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

Legend