BROCHANTITE. 81 



inclining to yellow and grey. Transparent ... 

 translucent. 



Hardness = 5-0 ... 55. Sp. Gr. = 212 ... 2-20, 

 Dr BREWSTEE. 



It is found in crystals and crystalline coats, associated 

 with rhombohedral Lime-haloide, at Strontian in Argyll- 

 shire. It resembles particularly the prismatoidal and hemi- 

 prismatic Kouphone-spars, with which it has been formerly 

 confounded. Before the blowpipe it loses first its water 

 and becomes opake, then it froths and swells up, but is 

 difficultly fusible. It gives a skeleton of silica with salt of 

 phosphorus. 



BROCHANTITE. 



MALACHITE. 



Brochantite, LEVY. Ann. of PhiL Oct 1824. p. 241. 



Prismatic. Combination observed similar to Fig. 

 21. without 2, and compressed between Pand P. 

 Inclination of o on o, adjacent = 150 3(X ; of M 

 on M, over the edge between o and o = 114 2(X, 

 of d on d, adjacent = 63 (X. LEVY. 



Cleavage, traces parallel to M. Surface, M black- 

 ish and dull, the remaining faces smooth and 

 shining. 



Colour emerald-green. Transparent. 



Hardness = 3-5 ... 4-0, nearly. 



According to the experiments before the blowpipe, made 

 by Mr CHILDREN, it consists of sulphuric acid and oxide 

 of copper. On account of its insolubility in water, it is 

 either a salt with excess of base, or, as Mr CHILDREN sup- 

 poses, it contains some other substance, as silica or alumi- 

 na, beside the two above mentioned. It is found in small 



VOL. III. F 



