Field Book of
Common Rocks
and Minerals
For identifying the Rocks and Minerals of the United States and interpreting their Origins and Meanings
By
Frederic Brewster Loomis
Late Professor of Mineralogy and Geology
in Amherst College
With 47 Colored Specimens and over 100 other Illustrations from Photographs by W. E. Corbin and drawings by the Author
G. P. Putnam’s Sons
New York and London
FIELD BOOK
OF
COMMON ROCKS AND MINERALS
Copyright, 1923, 1948
by
Frederick Brewster Loomis
Twenty-sixth Impression
Revised 1948
All rights reserved. This book, or parts thereof, must not be reproduced in any form without permission.
Made in the United States of America
Dedicated
TO
MY MOTHER
WHO ENCOURAGED ME WHILE A BOY TO GATHER MINERALS, ROCKS AND FOSSILS.
PREFACE
Everyone, who is alert as he wanders aboutthis world, wants to know what he is seeingand what it is all about. Here and there withthe aid of capable guides a few have been introducedinto the sphere of that wide and fascinatingknowledge of Nature which has been so rapidlyaccumulated during this and the latter part ofthe last century. It is a full treasure houseconstantly being enriched, but unfortunately thefew who have been initiated have soon acquireda technical language and habit, so that theirknowledge and new acquisitions are communicatedto but few. The public at large, not havingthe language nor an interpreter at hand, hascome almost at once to a barrier which few havethe time or patience to surmount.
Latterly it has become clear that the largestprogress cannot be made if the knowledge ofany branch of Science is confined to a few only.The most rapid advances have been made wheremany men are interested and enthusiastic. Inno science should there be a difficult barrierbetween the amateur and the professional student.All Nature is equally open for everyoneto study, and there should never be created obstaclesas by the use of terminology not easilyacquired by anyone. Of late these barriers haveviiibeen in part broken down and competent studentshave written guides which anyone canfollow, and soon begin to know the plants, trees,birds, insects, etc. So far no one has attemptedto make the study of minerals and rocks so directand simple that everyone can get a start. Mostbooks on minerals, and practically all those onrocks are written for school courses, and to saythe least chill any enthusiasm which is naturallyaroused by the finding of interesting lookingrocks or minerals.
The purpose of this book is first of all to providea means of identifying minerals and rocks bysuch methods as are practical without elaborateequipment or previous training: and second tosuggest the conditions under which the variousminerals and rocks were formed, so that, at thefirst contact, one may get a conception of theevents which have anteceded the mineral orrock which has been found. For this purposekeys have been worked out f