1891.] Mineralogy and Petrography. 661 
The density of. the crystals is 3.299. A small fragment of the same 
mineral from McKay’s Brook, Northumberland Co., N. S., was not 
large enough for analysis. Massive rose-colored eudialite™ from 
Magnet Cove, Ark., has a specific gravity of 2.810. Analysis gave: 
SiO, QuO, Ta,O,(??) FeO MnO MgO CaO NAO EO Cl Ign. 
$9.83. 45.45 >39 4237-637 AL. ARF A320 As Aa ee 
Sphene occurs at Magnet Cove, in small brown or brownish-yellow 
crystals, associated with the constituents of elzeolite-syenite. They are 
simple combinations of oP and —P. 
SIO, HO, FeQ MgO CaO Ign Sp.Gr. 
s87 30.84 39-35 “73 t. ee 3-457 
At the same locality, in a coarse-grained calcite, are crystals and 
crystalline grains of monticellite, associated with crystals of magnetite 
and apatite.. The habit of the rare mineral is short prismatic, with 
pyramidal terminations oP% and 2P% largely developed (axial ratio 
= .4337: 1:.5757). The hardness is S; density, 3.108. The min- 
eral, upon analysis, gave, as a mean of two sets of determinations : 
SiO, AlO, MnO FeO MgO CaO P,O, Ign 
33.40 TF 1:12 5.0% 20.61 35.24 2.03 2.2 



deducting the P,O, as apatite, which was present in the assay, the 
figures became : | 
SiO, ALO, MnO FeO MgO CaO _ Ign 
25:34. 19 3.27 5.25 21.64 34.21 2.40 
corresponding to (Mg,Mn,Fe),SiO,+Ca,SiO,. A light-gray selen- 
iferous bismuthinite, consisting of slender crystals imbedded in clay, 
yielded Genth:" Bi=77.54; S=14.06; Se= 8.80, corresponding 
to 4Bi,S,+Bi,Se, It probably came from Guadalajara, Mex. Its 
density is 6.306. As the mineral was sent to the author as a specimen 
of guanajualite, an analysis of a specimen of this from an old German 
collection was made in order to discover whether or not it should be 
regarded as a distinct species. The examination resulted in the figures : 
Bi = 68.86; S—4.68; Se= 25.50, corresponding to Bi,S, + 2BiSe,. 
Messrs. Melville and Luidgren ® have contributed to our knowl- 
edge of the minerals of the Pacific slope some interesting observations 
in cinnabar, metacinnabarite, struneyerite, and a few other rare sub- 
stances, among which are the recently described minerals knoxvillite 


10 Cf J. F. Williams. Amer. Jour. Sci., Dec., 1890. 
u Amer. Jour. Sci., May, 1891, p.402. 
12 Bull. U. S. Geol. Survey, No. 61. 
