ORDER IV. HEXAHEDR AL LIROCONE-MALACH1TE. 163 



other faces, with exception of the dodecahedron, 

 often curved. 



Lustre adamantine, not very distinct. Colour 

 olive-green, passing into yellowish-brown bor- 

 dering sometimes upon hyacinth-red and blackish- 

 brown ; also into grass-green and emerald-green. 

 Streak olive-green ... brown, commonly pale. 

 Translucent on the edges. 



Rather sectile. Hardness = 2-5. Sp, Gr. = 3-000, 

 BOUEXON. 

 Compound Varieties. Massive : composition 



granular, rare. 



OBSERVATIONS 



1. The hexahedral Lirocone-malachite consists of 

 Oxide of Iron 45-50 48-00. 

 Arsenic 31-00 18-00. 

 Oxide of Copper 9-00 0-00. 

 Silica 4-00 0-00. 

 Carbonate of Lime 0-00 2-00. 



Water 10-50 CHENEVIX. 32-00. VAUQUELIK. 



Exposed to a gentle heat, its colour is changed into red. 

 In a higher degree of temperature it intumesces, gives 

 little or no arsenic, and leaves a red powder. Upon char- 

 coal it emits copious fumes of arsenic, and melts in the 

 inner flame into a metallic scoria, which acts upon the 

 magnetic needle. 



2. The chief repositories of this Malachite are veins of 

 copper ores in the older classes of rocks, where it is ac- 

 companied by prismatic Copper-glance and pyramidal Cop- 

 per-pyrites, by prismatic Iron-ore, often in ochrey varieties, 

 and by rhombohedral Quartz. 



3. It is principally found in Cornwall, in several copper- 

 mines in the neighbourhood of Redruth ; but has been 



