CATALOGUE OF GEMS AND PRECIOUS STONES. 21 



worthless pebbles such as black and red jaspers, quartzite or white 

 milky quartz, or chalcedony. The agates range from an opaque 

 white and gray to highly translucent gray with black, dark brown, 

 reddish to yellow-brown dendritic markings. Those with the black 

 and dark brown markings are the most common. They show great 

 variation in size and delicacy of pattern. Some are small rounded 

 tufts, too dense to show individual lines, and others are as much as 

 2 or 3 millimeters across, exhibiting very delicate moss-like or sea- 

 weed-like markings. The original source of the gravel is supposed to 

 have been the White River formation of the vicinity, which is of 

 Oligocene age. (See further under Quartz.) 



LIST OP SPECIMENS. 



CHALCEDONY, common. 



GERMANY. 



Two gems, cabochon, one rectangular, one elliptical; pale cloudy gray; 41 

 by 29 by 5, 19 by 16 by 6 mm. Gift of George F. Kunz No. 803 



INDIA. 



Six stones, cabochon, three elliptical, two elongated octagon, one pear- 

 shaped; 36 by 27 by 8 to 18 by 15 by 6 mm No. 802 



UNITED STATES. 



California. 

 Muroc, Kern County: 



Cabochon, pear-shaped girdle; colorless and white mottled; 34 by 20 



by 6 mm No. 812 



Cabochon, pear-shaped girdle; gray and green, mottled; 28 by 21 by 

 8 mm No. 813 



Colorado. 



Cabochon, elliptical gii die; translucent with red color; 2.8 carats; 11 by 7 

 by 5 mm. (St. Stephen stone). Gift of J. B. Endicott No 815 



Virginia. 

 Fairfax, Fairfax County: 



Cabochon, circular girdle; pale cloudy gray; 10 by 7^im No. 804 



LOCALITY NOT RECORDED. 



Twelve stones, cabochon and tabular, elliptical girdles; cloudy brown- 

 gray; 46 by 35 by 4 mm. to 20 by 15 by 3 mm No. 807 



Four variously cut stones, one cabochon and one ring, elliptical girdles; two 

 pendant; pale gray; 25 by 20 by 6, 26 by 17 by 5, 42 by 12, 25 by 12 mm. . No. 546 



Four stones, cabochon, elliptical girdle; artificially colored yellow, three 

 banded; 38 by 29 by 8 mm. to 23 by 17 by 7 mm No 543 



Five stones, cabochon and table, elliptical and pear-shaped girdles; arti- 

 ficially colored yellow; 32 by 24 by 7 mm., 19 by 10 mm No. 806 



