Describe the different minerals that determine the color of granite.?

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Describe the different minerals that determine the color of granite.?

2006-09-25 11:35:54 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Other - Science

2 answers

quartz - colourless
alkali feldspars - white to pink
plagioclase feldspars - white to grey
hornblende - black
muscovite - shiney white and/or biotite - shiney black

+- small amounts of apatite (green), garnet (red), magnetite (black)

weathering of granite can change the colours as the feldspars change rapidly (in geological time) to kaolinite clay (white)

2006-09-25 20:39:11 · answer #1 · answered by Anonymous · 0⤊ 0⤋

Hi. The ratio of quartz to feldspar is one.

2006-09-25 18:39:07 · answer #2 · answered by Cirric 7 · 0⤊ 0⤋