CATALOGUE OF GEMS AND PRECIOUS STONES. 99 



rose-red to pink-colored kinds are called halas ruby; the yellow or 

 orange-red spinels are known as rubicette; the violet and purple ones 

 as almandine; the pale to sapphire-blue kinds as sapyliirine ; the 

 blacks as pleonast. 



Spinel occurs embedded in granular limestone, and with calcite in 

 serpentine, gneiss, and allied rocks; occurring also in cavities in the 

 ejected masses from certain volcanoes. Found also as rolled pebbles 

 in certain alluvials, such as those of Ceylon and Burma, where it 

 occurs in water-worn masses of fine colors in the channels of streams, 

 along with quartz, garnet, tourmaline, sapphire, zircon, and other 

 gem minerals. Spinel ruby is frequently found along with the ruby 

 corundum in the crystalline limestone of the ruby mines of Burma. 

 Most of the gem spinel comes from Ceylon, Burma, Siam, India, and 

 other eastern countries. Small crystals of good color are found in the 

 gem-bearing gravel of Expailly, France. The old lavas of Monte 

 Somma, Italy, afford small black crystals of great brilliancy. A pale 

 blue to pearl gray kind is found in the limestone near Aker, Sweden. 

 From Amity, New York, to Andover, New Jersey, a distance of about 

 30 miles, is a region of granular limestone and serpentine in which 

 localities of spinel abound, the crystals sometimes being fine enough 

 to afford green, black, brown, and, less commonly, red gems. The 

 localities near Franklin, New Jersey, yield crystals of various shades 

 of black, blue, green, and red, which will occasionally afford small 

 gems. While in some demand as a precious stone it is not as generally 

 sought as the ruby varieties of corundum. 



LIST OF SPECIMENS. 

 CEYLON. 



Step, rectangular girdle; red-violet; 3.15 carats; 10 by 8 by 5 mm. Isaac 



Lea collection No. 606 



Brilliant, square girdle; deep green; 2.40 carats; 9 by 4 mm No. 599 



Step, rectangular girdle; dark blue-green; 2.1 carats; 9 by 7 by 4 mm. 



Isaac Lea collection No. 608 



Step-brilliant, elliptical girdle; deep red; 1.88 carats; 9 by 8 by 4 mm. 



Isaac Lea collection No. 609 



Brilliant, square girdle; violet; 1.86 carats; 8 by 5 mm No. 596 



Step-brilliant, elliptical girdle; blue-green; 1.85 carats; 8 by 7 by 5 mm. 



Isaac Lea collection No. 611 



Step-brilliant, rectangular girdle; violet; 1.82 carats; 9 by 7 by 5 mm. 



Isaac Lea collection No. 607 



Step-brilliant, elliptical girdle; bright red; 1.645 carats; 7.5 by 7 by 4 mm. 



Isaac Lea collection No. 610 



Step-brilliant, square girdle; violet-red; 1.48 carats; 7 by 4 mm. Isaac Lea 



collection No. 613 



Step-brilliant, rectangular girdle; yellow-green; 1.466 carats; 7 by 6 by 5 mm. 



Isaac Lea collection No. 614 



Step-brilliant, circular girdle; dark smoky violet; 1.46 carats; 7.5 by 4 mm. 



Isaac Lea collection No. 612 



