Author: Ernest Newton Patty

Publisher: Theclassics.Us

Published: 2013-09

Total Pages: 112

ISBN-13: 9781230375953

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 edition. Excerpt: ... GLOSSARY A Amphibole, the generic name for the group of bisilicate minerals whose chief rock-making member is hornblende. It is often pre-fixed to those rocks which have hornblende as a prominent constituent. Amygdaloid, a vesicular igneous rock whose cavities have become filled with secondary minerals. The fillings are called amygdules. Aplite, an acidic phase of a granitic rock occurring as a dike. Argentiferous, silver-bearing. Argentite; Silver glance, a silver sulphide, Ag2S. Contains 87 per cent silver. Argillite, an argillaceous metamorphosed sedimentary rock, that may or may not possess a slaty clevage. Arkose, a sedimentary rock composed of material derived from the disintegration of granite, transported and redeposited with little sorting. Arrastre, apparatus for grinding ores by means of a heavy stone dragged around upon a circular bed. The arrastre is chiefly used for ores containing free gold, and amalgamation is combined with the grinding. Use now practically obsolete. Arsenolite, a white arsenious oxide, As2O3. Arsenopyrite; Mispickel, a sulpharsenide of iron; FeAsS. Contains 46 per cent arsenic. Augite, the commonest rock-making pyroxene. Contains large amounts of alumina and iron. Auriferous, containing gold. Azurite, blue copper carbonate, CuC03Cu (OH)2. Contains 46 per cent copper. B Back, that part of a lode which is nearest the surface in relation to any portions of the mine; thus the back of a level or a stope is that part of the unstoped lode which is above. Barite, sulphate of barium BaSO; also called heavy spar, from its high specific gravity. Basalt, in a broad sense basalt includes all the dark basic volcanic rocks. It is the most common extrusive rock. Basic, a general descriptive term for those igneous rocks...