1884] Mineralogy. 417 
appears to bear the same analogy to sarcolite that gehlenite does 
to meionite. The crystals are distinguished by an almost entire 
absence of cleavage. Hardness 5-6, spec. gravity 3.050-3.057. 
Luster vitreous to resinous. The composition, as determined by 
Mr. R. Haines, is as follows, the enclosed calcite being subtracted 
from the analysis : 
SiO, Al,O, FeO, CaO MgO KO NO PO- H,O 
36.74 19.79 1.33 38.16 77 A at, 240. can Se. 10 
From this the quantivalent ratio of basis to silica is calculated 
as 9 :© or 3: 2, thus placing the mineral among the subsilicates. 
The mineral is insoluble or only partially soluble in acids, but 
gelatinizes with them after ignition. 
Before the blowpipe it fuses at 3 with intumescence to a white 
glass. With the fluxes a slight reaction for iron is obtained. 
thin section examined under the microscope shows an ad- 
mixture of calcite, which causes momentary effervescence when 
the mineral is placed in acid. The ground-mass is a gray amor- 
phous, non-refracting substance resembling altered feldspar. Scat- 
tered through this are the unaltered crystalline fragments of a 
$3, transparent tetragonal mineral, doubly refracting except 
in sections across the axis. The whole appearance resembles that 
of certain Specimens of melilite, and shows alteration to have 
occurred hroughout the whole of the crystals. 
The microscopic characters are not those of a simple mineral. 
Dr. M. E. Wadsworth regards the colorless mineral (isotropie or 
tetragonal) as having replaced the gray amorphous substance, as 
though the latter had once occupied the entire space. 
The crystals are imbedded in blue calcite, and are associated 
with pyroxene, graphite, cubical spinel (see below) and other 
pricing They were given the author by Dr. A. E. Foote, who 
) tained them from the locality. 
3 diferc Species appears to be isomorphous with sarcolite, but its very 
. tine = physical and chemical characters indicate either a dis- 
wie Pecies or a pseudomorph. The absence of cleavage and the 
: ogeneous microscopic characters argue pseudomorphism. 
d emicaliy it is allied to gehlenite. The temporary name caco- 
kiesi referring to its imperfect cleavage, was suggested. The 
‘ mens are still under investigation—H. C. Lewss. 
FG i SPINEL—Close to the locality where the above mineral 
f te big » Were cubes of a hard, dark mineral, the corners of which 
film italy nearly black, and were frequently covered with a 
a transmitted oxide. Small fragments were transparent, and by 
rarely sm light black or smoky sea-green or bluish-green color, 
x T amethystine. It scratched quartz, and as shown by 
iae E a E 
voL, 
; 27 
