THE NONMETALLIC MINERALS. 



323 



oretitcr. Tlio prcviiiliiii;- colors tire white oi- s>-r(HMiish g'ray 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 consid(>ra])le extent and purity. 



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

 men No. 27065, U.S.N.M.), a,re used for making- slate pencils and tailors' 

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

 as agalmatolite (Specimens Nos. 37812, fromSonora, Mexico, and 27133 

 and 27131:, 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,^ the name is made to 

 include a large number of alteration products of white spodumene, 

 nepheline, feldspar, etc. Professor Heddle has described" 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 

 giv^en 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^Mg., Si30io, = 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 

 ♦ »7749 are characteristic. In nature it rarely occurs in a state of 

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

 Mineralogy: 



' System of Mineralogy, 6th ed., p. 621. ^ Mineralogical Magazine, IV, p. 215. 



