3B6 DESCRIPTIVE MINERALOGY. 



SCORODITE. 

 [From the Greek i^xopo^ov, garlic ; in allusion to its odour under the blowpipe.] 



Scorodite. Cleaveland, BeudarU, Phillips and Tkomson. — Cuixre Arseniat^ Ferrifere. Haity ? — Peritomcs 

 FIus-Haloid. Moks. — Cube Ore. Shepard? (Thb mineTal was incorrectly supposed to be an arseniate of 

 copper combined with oxide of iron.) 



Vii■i^^• Description. Colour leek-green passing into white, olive-green 



and liver-brown. Streak white. It occurs regularly crystallized. 

 The primary form is a right rhombic prism. Fig. 471. M on M' 

 ^ i it \20° W {Phillips). Cleavage imperfect parallel to the planes MM' 



of the prism, and to its lesser diagonal. Fracture uneven. Lustre 

 vitreous, inclining to adamantine. Translucent on the edges to semi- 

 transparent. Rather brittle. Hardness from 3 . 5 to 4 . 0. Specific 

 gravity 3.16 to 3.30. Before the blowpipe, it gives out an arsenical odour, and melts into 

 a reddish brown scoria which is attracted by the magnet ; with fluxes, it exhibits the bottle- 

 green colour characteristic of iron. It is soluble in nitric and muriatic acids. 



Composition. Arsenious acid 31 .40, protoxide of iron 36.25, sulphuric acid 1.54, pro- 

 toxide of manganese 4.00, lime 2.00, magnesia 2.00, water 18.00 {Ficinus). 



Geological Situation. This mineral is associated with arsenical iron pyrites and other 

 minerals, and occurs in white limestone. 



Orange County. Scorodite has heretofore been found in the United States, only on the 

 farm of Mr. B. Hopkins, near the village of Edenville in the town of Warwick. It is in the 

 form of minute crystals and druses of a leek-green, grass-green and greenish white colour. 

 Before the blowpipe it fuses readily, with the extrication of arsenical fumes, into a magnetic 

 scoria. It is associated with arsenical pyrites, iron sinter, oxide of iron, etc., and is found 

 in a vein in white limestone. 



IRON SINTER. 



Iron Sinter. Shepard. — Diarsenate of Iron. Thomson. — Untheilbarer Retin-Allophon. Mohs. 



Description. Colour yellowish grey, reddish or blackish brown. It occurs in kidney-form 

 pieces, soft, approaching to friable. Fracture coarse and earthy, sometimes conchoidal. 

 Lustre vitreous to dull. Soft. Specific gravity 2 . 40. Before the blowpipe, it intumesces, 

 and some varieties emit a strong arsenical odour, during which they are partly volatihzed. 



Composition. Arsenic acid 30.25, peroxide of iron "40.25, water with a trace of sulphuric 

 &cii 28.50 {Karsten). 



