Browse Items (1651 total)

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Peridotite, serpentinized, with plagioclase with harrisitic structure.

Serpentinized peridotite with plagioclase, olivine, plagioclase, clino-pyroxene, chromite. Secondary minerals include hydrogrossuaria as well as serpentine, chlorite, prehnite.

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yellowed and peeling corners

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yellowed and peeling corners

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Hand Sample: Porphyritic diabase with coarse to very coarse grained subhedral pink-green plagioclase laths approximately 3cm in length set in a gray-black matrix. Inclusions of matrix present within plagioclase laths. Weathers to orange-brown.

Holocrystalline, medium grained, anhedral, ophitic, dibastic crystals. Low silica percentage (46.3%) for a Diabase, bordering on ultramafic compostion. Calcite is present on weathered surfaces, but not on fresh surfaces. (FOV: 3.2mm)

Shows considerable fracturing, thin section examination shows ophitic texture

Ophitic texture in thin section, plagioclase exhibits some alteration to sericite

Ophitic texture in thin section, some opaques

Quarred for monumental stone, ophitic texture in thin section, minor amount of opaques