372 The American Naturalist. 
corresponding to H,(MnFeCa),PO,+ 4H,O. Reddingite is in pink 
white masses, and in orthorhombic crystals with an octahedral ] 
The axial ratio is a: 4:¢—=.8678: 1: .9485, and density 3. 
Their analysis yielded Mr. Wells: a 
i: a, FeO- MnO CaO HO = Quartz. 
34-90 17.13 34.51 -63 13.18 Pe 
ture and rhombic tabular habit.——The beautiful chalcopyrite ™ cx 
tals from the French Treek Mines, Chester Co., Pa., occur toget 
with pyrite ® imbedded in byssolite, thuringite, and calcite in p D 
in a magnetic iron ore. The principal type of the chalcopyrite is 
sphenoid ae often modified by a scalenohedron. All the fa 
striated, and frequently they are so much rounded as to p 
measurements of their interfacial angles. Twinned crystals are 
common, the combination possessing an hexagonal habit——The 
zeolite mordenite has been discovered by Pirsson ¥ in the cavity 
amygdaloidal basalt, forming fragments in a breccia near Hood 
in Western Wyoming. The mineral is in very small crystals, 
specific gravity lying between 2,119 and 2.179. -Their analysis yi 
SiO, =“ ALO, FeO, CaO MgO K,O Na,O HO — 
66.40 11.17 157 1 17 3.58 2.27 ori 
which is equivalent to 3RAL,Si,,O,,+ 20H,O, in which R rept 
potassium, sodium, and calcium. The mineral differs from pt 
containing more water, In crystallization it is monoclinic, 
S 
"7 Penfield. our. Sci., Sep., 1890, p. 207. 
'* Penfield. Ib., HI, XXXVII., p. 209. 
o « Wb. Sep., 1890, p, 
-o ES Moye. NL, thos, pay. 
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