Brush and Dana—Feairfield County Minerals. 35 
quartz, in which occasional brilliant cubes of pyrite are also 
imbedded. 
In addition to the above minerals, as original constituents of 
the same deposit, are amblygonite (hebronite), a a phosphate 
of manganese isomorphous with scorodite which we shall de- 
scribe under the name reddingite. re pas roducts we 
have apatite and quartz coating together crystals of eosphorite, 
vivianite in thin layers and crystals, besides other species, 
which as yet, owing to lack of sufficient material for examina- 
tion, we have been unable to determine. 
Furthermore, there are a variety of alteration products: each 
one of the manganesian phosphates yields on alteration a ‘lacie 
or purple phosphate of manganese and iron sesquioxides, and 
the rhodochrosite gives a pseudomorph of hydrated oxides. 
The second smaller nest discovered consisted almost exclu- 
sively of lithiophilite. Of the previously mentioned minerals 
rhodochrosite is the only one we have observed with it, and that 
occurs very sparingly. In addition, however, a peculiar green 
manganiferous apatite, spodumene and cymatolite are intimately 
associated with the lithiophilite, besides the black phosphate 
produced from its oxidation, and occasional crystals of uraninite 
and rasta green and yellow hydrate ted phosphates of uranium. 
the large amount of black oxidized material, rich in 
lithia, Sed with the first deposit it is probable that lithiophilite, 
or some other similar ar the triphylite group, formed one 
of the original constituents of that mass. In fact it was the dis- 
covery of lithia in the black product of decdkeition ton. and its ab- 
sence in eosphorite, triploidite and dickinsonite, which led us to 
make further search for the source of this alkali. ee 
in the deepest part of our explorations in the vein we struc 
small = uae ae us ae fresh unaltered mineral 
We wish here to express obligations to Mess 
Samael 1 is Penfield aiid ‘ovals z Wells of the Sheffield Labo: 
ratory, for the excellent analyses which their enthusiastic devo- 
tion to the work has enabled us to present in this paper. The 
carrying through of these ap 8 has involved in many cases 
more than usual difficulty, and we appreciate fully to what an 
extent the value of this article is dependent upon the skill and 
patient care with which these difficulties have been overcome. 
1. EospHorire. 
General physical characters.—EKosphorite occurs in prismatic 
crystals, sometimes of considerable size, which belong to the 
orthorhombic ey show a nearly perfect mac gee 
cleavage. It also and more commonly occurs massiv 
Specimens showing the cleavage finely, but eradaating "itile 
others which are shiek compact. The hardness is 5. For the 
