Harmotome
(Ba,K)_1-2(Si,Al)₈)O₁₆ · 6H₂O

     Harmotome is widespread in small quantities at Mont Saint-Hilaire and is indistinguishable visually from phillipsite.

PHYSICAL CHARACTERISTICS:

Color is usually colorless or white.
Luster is vitreous.
Diaphaneity is transparent to translucent.
Crystal System is monoclinic; P2₁/m.
Crystal Habits include very small clusters of cruciform twins
   or prismatic crystals on other minerals.
Cleavage {010} and {100} are distinct.
Fracture is uneven to subconchoidal.
Hardness is 4.5
Specific Gravity is approximately 2.38 g/cm³.
Streak is white.
Associated Minerals include aegirine, albite, amphibole group,
   analcime, ancylite, calcite group, catapleiite, cordylite, elpidite,
   eudialyte, fluorapatite, galena, microcline, monteregianite,
   natrolite, pyrophanite and titanite.
Distinguishing Features: Crystal habit.
Origin: Named in 1801 from the Greek amos, a joint, plus tome,
   to cut, referring to the morphology of its twinned crystals.

CLASSIFICATION:

REFERENCES:
MinRec 21:314 (1990), Dana 8:1664-1665 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

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