470 RECORD OF SCIENCE FOR 1887 AND 1888, 



Species. The hardness is 3, and the specific gravitj' 2.24. Associated 

 with it is the other iron sulphate called amarantite, which is in aggre- 

 gates of minute prismatic crystals. These are orange red in color, and 

 in cleavage and optical characters they approach hohmannite. They 

 are, however, less readily attacked by water. The composition of the 

 two minerals is the same, viz: re20:i2SO:j+7H20, the analyses being as 

 follows : 



SOg FeaOs U^O 

 Hohmanuitc : 33.84 35..58 30.00 = 99.50 

 Amarantite: 35.58 37.26 27.62 = 100.46 



An earlier analysis of hohmannite gave somewhat different results but 

 was made on less pure material. There is little doubt, therefore, that 

 both minerals are to be united under the above name. (Min. petr. Mitth., 

 1887, vol. IX, 397, 428.) 



Rorsfordite. — A new copper antimonide, analogous to the copper 

 arsenide, algodonite, and the silver antimonide, dyscrasite. It is a mas- 

 sive mineral, resembling native silver in color, with a high luster on a 

 fresh surface but soon tarnishing. The hardness is 4 to 5, and the 

 specific gravity 8.812, The mean of three analyses gave: 



Sb Cu 



26.86 73.37 = 100.23. 



The formula lies between OusSb and CueSb, the analytical results 

 agreeing very closely with Oun Sb2. It forms an extensive deposit 

 near Mytilene in Asia Minor. It is named after Professor Horsford by 

 A. Laist and T. H. Norton in Amer. Chem. Journ., vol. x, p. GO, 188-. 



Inesite. — A hydrated silicate of manganese and calcium, probably 

 the same mineral as that called rhodotilite by Flink (see below). It 

 occurs ill fibrous radiated forms, of a flesh-red color, in the Dillinburg 

 region, Germany. Hardness, (> to 7 ; specific gravity, 3.103. An anal- 

 ysis gave : 



Described by A. Schneider in Zeitschr. deutsch. geolog. Ges., 1888, 

 vol. XXXIX, p. 829. 



Ignatieffite. — A name given by K. K. Flug to a variety of alumiuite 

 from Bachmut in southern Russia. It occurs in considerable quantity 

 in reuiform concretionary forms and though impure may have technical 

 value. (Verb. Euss. Min. Ges., St. Petersburg, vol. xxiii, p. 116.) 



Ldnghanite. — A mineral of unusual comi)Osition, a silico-antimonate of 

 manganese and iron. It occurs in hexagonal prismatic crystals, often 

 complex in form and resembling apatite. It has an iron-black color, 

 a metallic luster and conchoidal fracture. The hardness is 6.5, the 

 specific gravity 4.918. An analysis yielded : 



Sb20s SiOx MnO FeO 



15,42 10,88 64.00 10.32 = 100.62. 



