292 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1921. 



THE GEM COLLECTION. 



In the row of flat topped cases extending through the center of 

 the hall is exhibited a collection of cut stones and gems known as the 

 Isaac Lea collection. The history of this collection is as follows : In 

 1884, Prof. F. W. Clarke, at the time honorary curator of the Division 

 of Mineralogy, prepared an exhibition of American precious stones 

 as a part of the United States National Museum's contribution to 

 the New Orleans Exposition. The same collection was displayed at 

 the Cincinnati Exposition the year following, after which it was re- 

 turned to Washington and incorporated in the mineral collection 

 of the Museum. In 1891, the collection was greatly augmented by 

 purchases from the estate of Dr. Jos. Leidy, of Philadelphia, and 

 exhibited at the World's Columbian Exposition in Chicago in 1893, 

 when it was returned once more to Washington. In 1894, Mrs. 

 Frances Lea Chamberlain bequeathed to the Museum a collection of 

 precious stones which had been made by her father, Dr. Isaac Lea. 

 Later, in 1897, her husband, Dr. L. T. Chamberlain, became honorary 

 curator of the collection and added a large number of desirable 

 specimens. On his death he bequeathed a sum of money the income 

 from which is used for its further increase. 



In addition to the above sources many specimens have been re- 

 ceived 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 in- 

 dividual stones are differentiated by labels. The exhibition as above 

 noted is comprised in a row of table cases down the center of the hall 

 (see pi. 16, fig. 1). At the west end of this row immediately to the 

 right of the entrance to the hall stands a large group of amethyst crys- 

 tals from Brazil. In the 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. 



The collection now comprises some 4.000 individual stones, includ- 

 ing not only those used for personal adornment, but as well such as 

 are used in the smaller works of art and utilitarian purposes. 

 Especial attention may be called to the cases of opals, both cut and 

 in the rough. Among the individual cut stones mention may be made 

 of the 57.5-carat green tourmaline from Maine, the unique 61-carat 

 yellow orthoclase from Madagascar, the blue zircons from Australia; 

 the 40 and 47 carat aqua marines from Connecticut and Siberia ; the 



