LEISURE HOURS AMONG THE GEMS [Illustration: CRYSTAL OF SAPPHIRE CEYLON Exact size. HAMLIN COLLECTION] LEISURE HOURS AMONG THE GEMS BY AUGUSTUS C. HAMLIN AUTHOR OF A TREATISE ON THE TOURMALINE FELLOW OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE MEMBER OF THE ROYAL SOCIETY OF ANTIQUARIES OF NORTHERN EUROPE CHEVALIER OF ST. ANNE, ETC. “Now in matter of the knowledge of the works of nature, I would have thee give thyself curiously; so that there be no sea, river, nor fountain of which thou dost not know the fishes; all the fowls of the air; all the metals that are hid within the bowels of the earth; together with the precious stones that are to be seen in the east and south of the world. Let nothing of all these be unknown to thee.”--RABELAIS. BOSTON AND NEW YORK HOUGHTON, MIFFLIN AND COMPANY The Riverside Press, Cambridge 1891 _Copyright, 1884_, BY AUGUSTUS C. HAMLIN. _All rights reserved._ _The Riverside Press, Cambridge, Mass., U. S. A._ Printed by H. O. Houghton & Company. DEDICATION. [Illustration] _Whatever of interest or value there is to be found in these pages is earnestly inscribed_ To the Memory OF JEAN ANDRÉ DE PEYSONNEL, _who ventured to announce to the men of science of the Royal Academies of Europe in the eighteenth century that the_ CORAL _was the product of animal life, and not of vegetable growth. In answer to his simple discovery and honest declaration, the naturalist was met with a storm of contempt and derision that eventually wrecked his happiness and his life._ CONTENTS. PAGE THE DIAMOND 13 THE EMERALD 285 THE OPAL 335 THE SAPPHIRE 367 THE DIAMOND.