Cleavage, parallel to P and the shorter diagonal of the 

 prism, rather perfect; parallel taw and M less distinct. 

 Fracture conchoidal. Surface, the prisms streaked in the 

 direction of the principal axis, parallel to that line : the rest 

 of the faces commonly rough. 



Lustre resinous. Color, aurora-red, several shades, lit- 

 tle differing from each other. Streak orange yellow . . . 

 aurora-red. 



Sectile. Hardness =1-5 ... 2-0. Sp. gr. =3-566. 



Compound Varieties. Massive : composition granular, 

 of various sizes of individuals, strongly connected. Frac- 

 ture conchoidal, uneven. 



1. Before the blow-pipe, upon charcoal, it burns with a blue flame, 

 and emits fumes of sulphur and arsenic. It is soluble in nitric, muriatic 

 and sulphuric acids. 



2. Analysis. 



By KLAPROTH. By LATJGIER. 



Sulphur , - - 31-00 - - - - 30-43 

 Arsenic - - * 69-00 .... 69-57 

 3. Some of the varieties of Realgar occur along with Orpiment, in 

 beds of clay, as at Tajowa in Hungary. It is found in small nodules along 



