This scholarly work by the Geological Survey of the United States is an authoritative resource on the mineral corundum. The book includes detailed information on the occurrence and distribution of corundum in the US, as well as its properties and uses. Any geologist or mineralogist should have this book on their shelf. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.