Book Description

Excerpt from Mineral Tables for the Determination of Minerals by Their Physical Properties The only apparatus needed for the tables is a pocket-knife, a horse shoe magnet, a pocket-lens, a piece of unglazed porcelain or streak-plate, and a scale of hardness consisting of nine minerals. This scale can be procured of any mineral dealer or can be made up from specimens in an ordinary collection of minerals. Colon - The color of a mineral is perhaps the most important property used in its identification, yet it is the most difficult to accurately describe. A mineral may have but one characteristic color, or it may occur in various colors and shades; consequently a mineral may be repeated several times in the tables. The color must always be judged by the fresh surface or fracture, and it should be homogeneous throughout the mineral. Vitreous minerals may often be discolored or stained by impurities, when they manifestly belong to the color less or white class. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.