THE NONMETALLIC MINEEALS. 



323 



greater. The prevailing colors are white or greenish gray to dull red, 

 often mottled. 



Occurrence. The material sometimes occurs, as in the Deep River 

 region (Chatham, Moore, and Orange counties), North Carolina, in com- 

 pact to schistose masses of beds of considerable extent and purity. 



Uses.- The more compact varieties, like that of Deep River (Speci- 

 men No. 27665, U.S.N.M.), are used for making slate pencils and tailors' 

 chalk, or French chalk, so called. The still more compact forms, known 

 as agalmatolite (Specimens Nos. 37812, from Sonora, Mexico, and 27133 

 and 27134, Japan) and pagodite, are used extensively by the Chinese 

 and Japanese for making small images and art objects of various kinds. 

 Dana states, however, that a part of the so-called Chinese agalmatolite 

 is in reality pinite and a part of steatite. The objects sold by Chinese 

 dealers at the various expositions of late years under the name of jade 

 stone are, however, of agalmatolite. 



FINITE: Agalmatolite in part. Composition, a hydrous silicate of 

 alumina and the alkalies. According to Dana, 1 the name is made to 

 include a large number of alteration products of white spodumene, 

 nepheline, feldspar, etc. Professor Heddle has described 2 a pinite 

 (agalmatolite) occurring in large lumps of a sea-green color, surround- 

 ing crystalline masses of feldspar in the granites of Scotland, and which 

 he regards as alteration products of oligoclase. The composition as 

 given is: Silica, 48.72 per cent; alumina, 31.56 per cent; ferric oxide, 

 2.43 per cent; magnesia, 1.81 per cent; potash, 9.48 per cent; soda, 0.31 

 per cent; water, 5.75 per cent. 



14. SEPIOLITE; MEERSCHAUM. 



This mineral is a hydrous silicate of magnesia, having the composi- 

 tion indicated by the formula H 4 Mg 2 Si 3 O 10 , = silica 60.8 per cent; mag- 

 nesia, 27.1 per cent; water, 12.1 per cent. The prevailing colors are 

 white or grayish, sometimes with a faint yellowish, reddish, or bluish 

 green tinge. It is sufficiently soft to be impressed by the nail, opaque, 

 with a compact structure, smooth feel, and somewhat clay-like aspect; 

 rarely it shows a fibrous structure. Specimens Nos. 62545, 66861, and 

 67749 are characteristic. In nature it rarely occurs in a state of 

 absolute purity. The following analyses are quoted from Dana's 

 Mineralogy : 



1 System of Mineralogy, 6th ed., p. 621. 2 Mineralogical Magazine, IV, p. 215. 



