Faceted, egg-shaped, 7000-carat rock crystal from Brazil. The goldstand is inset mostly with Montana sapphires. The gem was cut andthe stand was designed and constructed by Capt. John Sinkankas ofCalifornia. (7¼ inches high in all.)
Gems
in the
SMITHSONIAN
INSTITUTION
by PAUL E. DESAUTELS
Associate Curator
Division of Mineralogy
WASHINGTON, D. C.
1965
SMITHSONIAN
INSTITUTION
PUBLICATION
No. 4608
LIBRARY OF CONGRESS
Card No. 65-60068
CONTENTS
- The National Gem Collection 1
- The Study of Gems 3
- The Shaping of Gemstones 10
- Gem Substitutes 20
- Gem Lore 24
- The Principal Gem Species 27
- Some Notable Gems in the Collection 70
Prof. F. W. Clarke, former honorary curator ofthe Division of Mineralogy who assembled theSmithsonian Institution’s first gem collection in1884.
Dr. Isaac Lea, Philadelphia gem collector whosecollection was the nucleus around which theSmithsonian Institution’s gem collection has beenbuilt through the years.
Dr. Leander T. Chamberlain, son-in-law of Dr.Isaac Lea, who became honorary curator of theSmithsonian Institution’s gem collection in 1897.Income from his bequest is used to purchasegems for the Isaac Lea gem collection.
1
THE NATIONAL GEM COLLECTION
Man has been using certain mineral species for personaladornment since prehistoric times. However, of thealmost 2000 different mineral species, relatively few,perhaps only 100, have been used traditionally as gems. To beused as a gem, a mineral species must have durability as well asbeauty. Lack of durability eliminates most minerals as gems,although some relatively fragile gem materials such as opal areprized because of their exceptional beauty. Actually, some gemmaterials are not minerals at all. Pearl, amber, jet, and coralare formed by