-T. S. Hunt on Algerite. 351 
Ant, XXXVII.—Remarks on the Mineral species Algerite ; by 
T. S. Honr. 
In this Journal for July, 1849, I published a description by 
Mr. Alger, of a mineral from Franklin, N. J., together with an 
analysis of it by myself, from which I was led to consider it a 
new species, and to give it the name of Algerite. It was again 
analyzed by Mr. R. Crossley, whose results will be found in this 
Journal for July, 1850. The mineral had been described as hav- 
ing the form of an oblique rhombic prism, M:M = 94°, but Mr. 
Dana has satisfied himself that the crystal is really a square prism. 
The hardness is 3-0—3-5 (Alger, Crossley); density 2.697— 
2712 (Hunt), 2:78 (Crossley). The mineral which is imbedded 
| 
Le 
in a white coarse-grained crystalline limestone, is subject to de- 
composition in the weathered portions of the rock, but as I stated 
in my paper, ‘ the crystals selected for analysis were hard, semi- 
translucent and undecomposed ; their powder when elutriated 
and carefully dried, was of a buff color, which was not changed 
by ignition.” Mr. Crossley remarks that in his case “many of 
_ the crystals were incrusted with idocrase, and in some instances 
penetrated so much that it required great caution to secure por- 
tions free from that mineral.” He rejected all decomposed por- 
ions, and analyzed only pure honey-yellow fragments. ‘The 
tesults of the two analyses are as follows : 
; Hunt. CrossLey. 
Silica, - - 49°82 . mM « 49°96 
lumina, - - 24°91 > - - 24-41 
Peroxyd of iron, = - 1:85 - - - 148 
Magnesia, - _ 115 ‘ : : 5:18 
zotash, : 10°21 . : . 9-97 
i; Soda, 
Carbonate of lime, - 3:94 . - - 421 
Water, “ - 157 - . . 5:06 
99°45 10027 
. 
A subsequent incomplete analysis gave me, Silica 49-42, alu- 
Mina 25-67, peroxyd of iron 1:93, carbonate of lime 3:57, water 
publ ished in the last volume of this Journal, of which see 
