2 BULLETIN 118, UNITED STATES NATIONAL MUSEUM. 



In 1894 Mrs. Frances Lea Chamberlain bequeathed to the museum 

 a collection of precious stones which had been assembled by her father, 

 Dr. Isaac Lea (pi. 1). Her husband, Dr. L. T. Chamberlain (pi. 2), 

 who subsequently (1S97) became honorary curator of the collection, 

 added a large number of specimens, and on his death bequeathed a 

 sum of money, the income of which is to be used for their further 

 increase. 



In addition, many specimens have been received throughout this 

 period as gifts from individuals and transfers from the United States 

 Geological Survey. These various collections have been combined, 

 and are now exhibited as "The Isaac Lea Collection," although the 

 individual stones are differentiated by label. The exhibit at present 

 is comprised in a row of table cases, extending down the center of the 

 Mineral Hall. (See pi. 3.) At the west end of this row, immediately 

 to the right of the entrance to the hall, stands a large group of ame- 

 thyst crystals from Brazil. In table cases fronting the windows on 

 the south side of the hall are other series illustrating the properties 

 of precious stones, their appearance in the rough as contrasted with 

 the cut form; gem minerals in the matrix or as occurring in nature, 

 and artificial and imitation stones. Finally, an upright case between 

 the windows at the center of the hall contains many semiprecious 

 stones — that is, stones used in the manufacture of small ornaments, 

 rather than for personal adornment. 



It ma}- be added that in building up the collection an attempt has 

 been made to show the possibilities of commonplace material; that 

 there is a goodly number of stones, in themselves of little intrinsic 

 value, which when properly cut and mounted are not merely beauti- 

 ful, but have the additional value of being out of the line of the usual 

 material sold in shops. In this connection particular attention may 

 be called to the cabochons of silicified wood, obsidian, epidotic granite 

 (unakite), and green feldspar (amazonstone). 



