NaFe2+Al(BOSi18)(OH)(OH)
Schorl has only been recently identified from a pegmatite-hornfels contact specimen from László Horváth. The species was identified by microprobe by Bob Gault from the Canadian Museum of Nature.
PHYSICAL CHARACTERISTICS:
Color is usually dark brown.
Luster is vitreous.
Diaphaneity is opaque to translucent.
Crystal System is hexagonal;
Crystal Habits include embedded prismatic crystals to 1.5 cm.
Cleavage is not apparent.
Fracture is conchoidal.
Hardness is 7.5
Specific Gravity is approximately 3.13 g/cm
Streak is grayish white to bluish white.
Associated Minerals include corundum, eudialyte, ferrocolumbite,
franconite, gmelinite, gobbinsite, gonnardite, hercynite, mica group,
molybdenite, natrolite, paranatrolite, quartz, rutile, siderite,
spessartine and synchysite.
Distinguishing Features: Crystal habit and color; brittle.
Origin: Named in ~1524, for a word probably meaning worthless
by 1747, used specifically for a tourmaline.
CLASSIFICATION:
Dana System
# 61.3.1.10
Strunz Classification
# VIII/E.19-50
REFERENCES:
Dana 8:1263-1264
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
¤¤¤