GEO 2163 Lecture Notes - Lecture 8: Riebeckite, Glaucophane, Blauw-Wit Amsterdam
21 Sep 2017
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Document Summary
Light to dark green, blue, brown, colorless, white, gray. White or grayish white, pale shades of blue, green and yellow. Parallel extinction in longitudinal sections, pale pink to green pleochroism. Id: white forms of diopside are occasionally fluorescent. bustamite. Longitudinal sections typically rectangular. two good cleavages parallel to the {210} prism faces that intersect at 88 . Crystals may also be somewhat elongated, and usually have good terminations. , bladed, radiating, fibrous, as cleavage fragments, and in disordered aggregates of elongated crystals. May also be in v-shaped penetration twins, and crystals from certain localities have partially hollow or dissolved etchings. Often as prismatic crystals with a rectangular or octagonal cross section. Also in short, stubby crystals with a flattened slightly pyramidal termination. Other forms are columnar, grainy, massive, fibrous, and in disordered aggregates of rectangular crystals. May also be in penetration twins with v- shaped saddles. Crystals from certain localities have partially hollow etchings.
