CATALOGUE OF GEMS AND PRECIOUS STONES. 13 



and imitation emerald (green glass). Other varieties of beryl show- 

 no spectrum. Other distinctive characters are color, slight pleochro- 

 ism, specific gravity, refractive index, and weak double refraction. 

 Beryl occurs chiefly in granitic pegmatites and related formations. 

 The famous emerald deposits of Muzo, Colombia, South America, are 

 in a limestone thought to have been metamorphosed by solutions 

 accompanying the intrusion of pegmatite dikes. All the transparent 

 varieties of beryl are of more or less value as precious stones; they 

 are usually cut facetted. The emerald is considered of greatest value, 

 though many of the aquamarine varieties are of great beauty. 



LIST OF SPECIMENS. 



BERYL, common, golden, and caesium. 



BRAZIL. 



Brilliant, circular girdle; colorless; 4.67 carats; 12.5 by 6 mm No. 738 



Step-brilliant, oval girdle; yellow-green; 1.269 carats; 9 by 6 by 3 mm. 



Isaac Lea collection No. 743 



Step-brilliant, elliptical girdle; colorless; 0.895 carat; 9 by 5.5 by 3.5 mm. . No. 740 



RUSSIA (ALABASHKA, URAL MOUNTAINS). 



Step-brilliant; rectangular girdle ; yellow; 17.46 carats; 18 by 14 by 10 mm. No. 714 



Table, rectangular girdle; yellow; 9.27 carats; 16 by 13 by 7 mm No. 715 



Step-brilliant, rectangular girdle; green-yellow; 3.126 carats; 10 by 8 by 6 



mm No. 718 



Step-brilliant, rectangular girdle; yellow; 3.113 carats; 12 by 9 by 5 mm.. No. 7]6 



Brilliant, rectangular girdle; pale yellow; 1.73 carats; 8 by 7 by 6 mm No. 717 



Brilliant, circular girdle; pale yellow; 1.31 carats; 8 by 5 mm No. 719 



SIBERIA. 



Table, rectangular girdle; yellow-green; 21.46 carats; 31 by 16 by 6.5 mm.. No. 713 



UNITED STATES. 



Connecticut. 

 Litchfield County: 



Brilliant, circular girdle; yellow; 1.73 carats; 8 by 6 mm No. 1036 



Brilliant; circular girdle; brown-yellow; 1.47 carats; 7.5 by 6 mm. 



Gift of New England Mining Company No. 780 



Brilliant, circular girdle; green-yellow; 1.09 carats; 7 by 5 mm. Gift 



of New England Mining Company No. 782 



Brilliant, circular girdle; brown-yellow; 0.987 carat; 6.5 by 5 mm. Gift 

 of New England Mining Company No. 784 



Maine. 



Mount Apatite, Auburn, Androscoggin County: 



Brilliant, circular girdle; very pale pink; 1.19 carats; 6.5 by 5 mm.. No. 1836 



Topsham, Sagadahoc County: 



Brilliant, circular girdle; green-yellow; 23.01 carats; 14.5 by 11 mm. 



(Set in gold band) No. 1031 



Brilliant, circular girdle; green-yellow; 5.25 carats; 12 by 7.5 mm No. 1032 



Brilliant, circular girdle; yellow-green; 4.155 carats; 11 by 7.5 mm No. 1035 



Brilliant, circular girdle; yellow-green; 3.275 carats; 10 by 7 mm No. 1033 



Brilliant, circular girdle; yellow-green; 1.S8 carats; 8.5 by 5.5 mm No. 1034 



