Diabase Porphyry Dike
Hand Sample: Hypocrystalline, porphyritic, diabase with subhedral plagioclase and alkali feldspar (weathered to green) crystals approximately 1cm in length. Matrix is brown-black color. Weathered to white. Intensive weathering on one side to light brown.
Thin Section, XPL: 25% medium-grained subhedral plagioclase crystals in a matrix of green and dark green aciciular grains with low birefringence. Opaques present.
Western Minerals, Inc.
Is Part Of
St. Francois Mtns. Batholith, Missouri
Purchased from Western Minerals, Inc.
Number of Thin Sections