332 On Minerals accompanying Chromie Iron. 
Art, XXXVI.—On Minerals accompanying Chromic Iron; 
b 
y Tsomas H. Garrett. 
In a former essay in this Journal, (vol. xiv, p, 45,) I embraced 
only chromic iron, and in the present I propose to introduce sev- 
eral of the minerals accompanying it. 
Kimmererite.—This beautiful mineral occurs in considerable 
quantity in chromic iron and its associated serpentine at Wood’s 
Pit, and at the mine on the line between Pennsylvania and Ma- 
tyland, a few miles from Texas, Lancaster Co., Pa. It forms 
vein-like projections in the ore and serpentine, or lines seams bé 
agonal prism. ‘The form is right rhombic, presenting hexagonal 
tablets with bevelled edges. The combinations are the vertical 
rhombic prism with the large main end plain and small Jateral end 
planes, (forming a hexagon,) a lateral rhombic prism on the edges 
of the end planes, and the octahedron replacing the edges of the 
vertical rhombic prism. 
The following are the results of my analysis of a pure spec 
men, between fibrous and foliated, and selected with care. 
Silica, 37-657 
Oxyd of chrome, . é ; 3-604 
Alumina, . : ; ‘ 11:823 
Magnesia, . F , : Q4-974 
ime, : : ; : 4113 
Protoxyd of iron, . : 2-499 
Protoxyd of nickel, i 0672 
er, ’ . ’ 13-582 
98-924 
_ The simplest formula accordin lysis would be 
a He simples g to the analysis ° 
2(R20s, 3Si0:)+11(RO, HO), And here I may be allowed © 
draw attention to a remarkable feature among some of the ray) 
merous taleose minerals ; that in a large proportion of them t 
number of equivalents of water and of RO bases 18 ed’ 
Hartwall’s formula for Kammererite is 2(RO SiOs)+ R202, S10? 
+6HO, although 54HO satisfies the analysis more exactly. 
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