50 CU. Shepard, Jr.—A new mineral, Pyrophosphorite. 
The mineral is generally snow-white and opaque, with here 
and there aslight tinge of bluish-gray. The white portion is = 
and has an earthy fracture like magnesite; the grayish—c 
stituting perhaps one-third of the mass—is small- bothyoidal 
like gibbsite, and is somewhat the harder of the two. 
The specific gravity varies between 2°50 and 2°58; hardness 
between 3 and 8°. Before the blowpipe it melts with diffi- 
culty on the eles to a whitish enamel. 
The following are the results of several chemical analyses of 
the mineral, as ‘executed on two different portions of material : 
1st Series. 2d Series. Mean. 
ee on imitans. wie OBOO. 6 eas 0°390 
Rar os Sot Bes Se 44°50 44°424 44°462 
Ma: meee (AL a. eet 3°141 3°090 
Stloberie WGd 0°57 0°687 0°628 
Eoeephoric A010. ods aes « BOOT 50°629 50°799 
Silic =i pe gp OE | ge 0°434 0°367 
Oxide of iron and alumina .--- 0°437 0°437 
100°1738 
If we add together the adventitious ingredients, viz: the 
pyrophosphates of iron oe alumina (taking an equal portion 
of phosphoric acid as the oxide of iron sehen the 
sulphate of lime, silica and ‘cs on ignition, we obtai 
ae sank 
BLA sole aay of iron and alumina -_-.---- 0°874 
Sulph Mie siud oak Peelers ee ee 
Silica Siwalesse bas eee ee Ce Bee 0°367 
AO Ob, SOWICION 5 0 as 2 a ns oe ee 
2°699 
There remain, 
t. 
Mare tid co's apie 44°022 or 45°16 
ee 3°090 3°17 | on raising the 
Phasphoris acid 50°362 51°67 2 ihe 4 per cent. 
ee 0 per cent, 
97°474 100°00 
The above composition agrees with the formula 
2MgO, P,0,+4(5Ca0, 2P,0,)* or2MgO, P,0,+4 } ocaO FO" 
which would require the following amounts of 
By calculation. Actually found. 
Ene ors sas 45°20 per cent. 45°16 per cent. 
Magnesia. --- ---- oo 8°17 
Pheaphicks baa 51°57 51°67 
100-00 | 100-00 
: Ca,P,0 
* Expressed according to atomic system Mg,P,0, +44 Cro ; 
