G. J. Brush.—Mineralogical Notices. 247 
product of the alteration of this variety of tourmaline; in many 
instances cavities in the rubellite are filled with the nacreous 
substance. It is also intimately associated with lepidolite, some- 
times in extremely minute scales, and not unfrequently in hem- 
ispherical aggregations; more rarely it is found in distinct six- 
sided prisms, which are bent into a vermicular form like some 
varieties of chlorite. In most cases it occurs so mixed with the ~ 
| tourmaline and lepidolite as to preclude the possibility of its 
being selected free from these minerals. 
With salt of phosphorus, gives a skeleton of silica. It is par- 
Caped identification. When thrown down by ammonia, it seems 
Somewhat less bulky and floculent in its character, and is much 
More easily washed than is usual with alumina; it, however, re- 
acts blue when treated with nitrate of cobalt, and with the small 
quantity under examination I have been unable to identify the 
4 and was insoluble in carbonate of ammonia, and did not. 
Teact for either fluorine, boracic or phosphoric acids. Its sul-_ 
r Mr. Peter 
Collier, assistant in this laboratory. For analysis, the mineral 
