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Staurolite:
Neosilicates (Basic silicate of iron and aluminum, often with some magnesium and zinc) Fe2Al9Si4O22(OH)2 AKA: |
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System: Monoclinic (pseudo-orthorhombic); in single or twinned crystals. Single crystals are prismatic and show pseudohexagonal cross section; twinned crystals show two individual crystals intergrown at nearly 60 degrees or nearly 90 degrees. Appearance: Yellowish brown, reddish to brownish black; weathering to gray; vitreous, dull; streak white. Physical Properties: Hardness: (7.0 - 7.5); Specific gravity: (3.7 - 3.8). Cleavage: poor, one direction lengthwise; fracture, uneven to subconchoidal; translucent to opaque; brittle. Similar species: The twin crystal form is sufficient to distinguish staurolite from tourmaline. Occurrence: Staurolite occurs with albite, biotite and sillimanite in gneiss and schist of regional metamorphic rocks. The famous locality of Pizzo Forno, Switzerland has yielded choice specimens. In North America, beautifully twinned and single crystals have been found in Maine, New Hampshire, Georgia, New Mexico and California. Miscellaneous: The name is from the Greek stauros, "cross", in reference to the commonly crosslike twinned formed. The right-angled staurolite penetration twins are popular as good luck charms. Transparent single crystals are occassionally cut into gems. Conventional Wisdom: Represents four elements and the joining of spirit with earth/matter. This mineral is a talisman of good luck. It can also be used to provide a connection to information from the ancients of the Middle East; it is said the the cruciform configuration of this stone was used to heal Richard the Lionhearted of a malarial-type disorder during the Crusades. It can provide for an overpowering relief in situations of stress and can eliminate depression and addictive personality traits. Belongs to the Astrological Sign of Pisces. |