1911 Encyclopædia Britannica/Petrology Wikisource, the free .
Apr 20, 2018 . General questions as to the nature, origin and classification of rocks and the . an arenaceous series such as sand (some with glauconite), sandstone, .. Some are very largely made up of remains of animals or plants, more or less .. Thus tourmaline may be brown, yellow, pink, blue, green, violet, grey or.Live Chat