96 BULLETIN 118, UNITED STATES NATIONAL MUSEUM. 



The mineral may be distinguished by its softness, color, and by 

 chemical tests. It occurs as a secondary product in rocks of many 

 kinds, both igneous and metamorphic. It is used mainly as an orna- 

 mental stone and is too soft to be of great value as a gem. The 

 variety williamsite is sometimes cut cabochon and used in scarf pins, 

 as are also the fibrous forms. A beautiful variety from the Yu-Yen 

 district of South Manchuria, China, is often carved into various 

 forms and sold to the unwary for jade. According to Dr. J. Morgan 

 Clements it is known locally as Yu Yen Shi (Stone of Yu Yen), or 

 Yu Yen Yue (Jade of Yu Yen). 



LIST OF SPECIMENS. 



SERPENTINE, common. 



UNITED STATES. 



California. 



San Francisco, San Francisco County: 



Flower ornament; gray-green; 27 by 20mm. Gift of Dr. R. E.C.Stearns. No. 371 



Massachusetts. 

 Newbury port, Essex County: 



Necklace of 51 beads; light and dark green; average, 12 mm. diameter. No. 1644 



SERPENTINE, variety BOWENITE. 



Rhode Island. 

 Smithfield, Providence County: 



Flat cabochon, elliptical girdle; dark olive green; 29.26 carats; 28 



by 22 by 7 mm. Gift of George F. Kunz No. 373 



Cabochon, circular girdle: pale yellow: 3.11 carats; 9.5 by 6 mm. 

 Gift of George F. Kunz No. 374 



SERPENTINE, variety SATELITE. 



California. 

 Visalia, Tulare County: 



Cabochon, rectangular girdle; gray-green with silky luster; 152.35 carats; 



39 by 35 by 15 mm No. 376 



Cabochon, pear-shaped girdle; gray -green with silky luster; 9.01 carats: 



23 by 12 by 7 mm No. 375 



SERPEPENTINE, variety WILLIAMSITE. 



Pennsylvania. 

 Wood's Mine, Lancaster County: 



Cabochon, circular girdle; bright green; 5.13 carats; 10 by 7 mm. Gift 



of Dr. Robert H. Lamborn No. 372 



Silicified Wood. — See under Chalcedony. 



SMITHSONITE. 



Composition. — Zinc carbonate, ZnC0 3 . 

 Crystallization . — Hexagonal (trigonal) , rhombohedral. 

 Color. — White when pure, but often yellow, green, or blue, owing 

 to the presence of impurities, especially copper carbonates. 



