44 G. E. Moore on Brushite, a new Mineral. 
possesses an odlitic structure and a singe white color, inter- — 
spersed with small spots of pure w 
The mineral is in the form of ae but very perfect and bril- 
liant crystals, with a cleavage in the direction of their greatest — 
length nearly equal to that of selenite, the Jaminz being also — 
slightly flexible, as in the case of the latter species. Hardness, — 
2° ecific ‘gravity, 2208 (mean of two determinations). — 
Color yellowish white. Transparent. Lustre vitreous, splendent, 
inclining to pearly on the cleavage faces. 4 
When heated in a closed tube before the blowpipe, it whitens 
and gives off water at an incipient red heat. In the platinum — 
forceps, it fuses with intumescence at about 2 on von Kobell’s” 
scale, tinging the flame with the peculiar green characteristic of 
phos osphorie acid. The button formed by fusion crystallizes on 
cooling, showing numerous brilliant facets. It readily dissolves, — 
even in coarse crystals, in dilute nitric and chlorhydric acids. 
A qualitative analysis revealed the presence of lime, phospho- 
ric acid and water, with barely discernible traces of magnesia 
and alumina. 
The quantity of mineral at my disposal was very small, 
scarcely exceeding one gram in weight. 
following analyses, the water was determined in 0-2 gram, the 
remaining 0°3 gram being employed in the determination of the 
jime and “phosphoric acid. The ha was as follows 
4 
— 
2. 
Lim - - fs 65 32°73 
Phosphoric aeiay: Sree Se BO 41°32 
Water, : * - - 26°33 26°40 
100-48 100°45 
These figures agree exactly with the composition of the neu- 
tral tri-basic phosphate of lime, 2CaO, HO, PO,, with the addi- 
tion of four = uivalents of water of crystallization (2CaO, HO, 
PO, +4aq), v 
2Ca0, - - - . 56-26 Po 32°59 
POs, ee es 41°34 
4 aq, + J 6 2s ae Oe 26:07 
17262 100-00 
Tn the polarizing microscope, the mineral shows a vivid suc — 
€ession of colors. A sample has been sent to Prof. J. D. Dan 
pi has kindly undertaken the study of its crystallograp. 
characters, and I hope in a short time to be able to communice 
the results of his investigations to the Academy. : 
It is with great pleasure that I dedicate. this species to P: 
G. J. Brush, of Yale College, to whose unwearied zeal and effi 
cient |: abors American pe binat stands so deeply indebted. 
San Francisco, Cal., Sept, 18 
