Excerpt from Petrographic and Ceramic Properties of Pennsylvanian Shales of IllinoisThe fact that all. Shales of equivalent fraction A content do not have the same green properties is evidence, if any is need ed, that these properties are not controlled solely by the amount of clay mineral and by the amount of material finer than mm. Shales with the same amount of frac tion A but composed of different kinds of clay mineral will not have the same green properties. Shales, furthermore, with the same amount Of fraction A and the same kind Of clay mineral it With different tex tural attributes will not have the same green properties. Plotting of the fraction A con tent against ceramic properties permits an analysis of the effect of'various factors on the ceramic properties of the Shales.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.