34 BULLETIN 118, UNITED STATES NATIONAL MUSEUM. 



mans Bar, and Yogo Gulch, where they occur in a pyroxenite and as 

 pebbles more or less rolled in the sands resulting from its disintegra- 

 tion. The Montana gems rarely exceed one-fourth to one-half inch 

 in length and range in color from light green, light blue, steel blue, 

 bluish red, light red, and intermediate shades; frequently the colors 

 mentioned will appear red or assume a reddish tinge by artificial 

 light. They are usually dichroic and often blue in one direction and 

 red in another. (See pi. 6.) 



Rubies of a high degree of perfection are now produced artificially 

 and their manufacture has become a matter of trade importance. 

 The artificial stone, in crystallization and composition, is identical 

 with the natural. 



CORUNDUM, variety RUBY. 

 CEYLON. 



Step-brilliant, heart-shaped girdle; pale violet red ; 6.84 carats; 13 by 10 



by 7 mm. Isaac Lea collection No. 198 



Step-brilliant, elliptical girdle; violet red; 4.193 carats; 11 by 7 by 6.5 mm. 



Isaac Lea collection No. 197 



Step-brilliant, elliptical girdle; pale red; 3.5 carats; 10 by 7.5 by 6 mm. 



Isaac Lea collection No. 14 



Step-brilliant, elliptical girdle; very pale red; 2.754 carats; 9 by 7.5 by 5 mm. 



Isaac Lea collection No. 16 



Step-brilliant, elliptical girdle; violet-red; 1.265 carats; 6.5 by 6 by 5 mm. 



Isaac Lea collection No. 202 



Step-brilliant, square girdle; deep red; 0.884 carat; 6 by 3 mm. Isaac Lea 



collection No. 201 



Step-brilliant, square girdle; deep red; 0.81 carat; 5 by 4 mm. Isaac Lea 



collection No. 200 



Step-brilliant, rectangular girdle; deep red; 0.81 carat; 6 by 5 by 4 mm. 



Isaac Lea collection No. 205 



Step-brilliant, irregular girdle; deep red; 0.737 carat; 7.5 by 6 by 3 mm. 



Isaac Lea collection No. 203 



Brilliant, elliptical girdle; pale red; 0.70 carat; 6 by 5 by 4 mm. Isaac Lea 



collection No. 209 



Step-brilliant, rectangular girdle; deep red; 0.64 carat; 5.5 by 4.5 by 3 mm. 



Isaac Lea collection No. 208 



Step-brilliant, circular girdle; deep red; 0.627 carat; 5.5 by 3 mm. Isaac 



Lea collection No. 206 



Step-brilliant, elliptical girdle; deep red; 0.625 carat; 6 by 4.5 by 3 mm. 



Isaac Lea collection No. 207 



Step-brilliant, rectangular girdle; pale, cloudy red; 0.44 carat; 5 by 4 by 



2.5 mm. Isaac Lea collection No. 69 



One lot of 239 small gems of which 228 are cut and 11 uncut. Mostly step- 

 brilliant, various girdles; red; total weight, 18.36 carats No. 219 



UNITED STATES. 

 Montana. 



Brilliant, circular girdle; red-violet; 2.165 carats; 8 by 3 mm, Isaac Lea 

 collection No. 1019 



Brilliant, circular girdle; very pale red; 1.215 carats; 6 by 4 mm. Isaac Lea 

 collection No. 1021 



