MANUAL OF NATURAL HISTORY. 599 



at Almaden in Spain ; 2, united with silver 

 as "Native Amalgam/' brittle, H. 3--3'5, sp. 

 gr. 14 ; 3, combined with sulphur, as " Cinna- 

 bar/' its most important ore, H. 2--2'5, sp. gr. 

 8, in small red, six-sided prisms, massive, 

 granular and steel-gray, or in fine red powder 

 (" Native Vermilion"), mostly in slate rocks 

 and also in coal formations in China and 

 Japan, in Idria, and in Spain, in Brazil, Peru, 

 Mexico, and California. Symb. Hg. 

 3. FAMILY, Kuprides, Minerals consisting of, or 

 containing principally, copper. Occurs 1, na- 

 tive, in amorphous masses, or octohedral crys- 

 tals, H. 2-5-3, sp. gr. 8'667, in most copper 

 mines ; dissolves in nitric acid, giving off 

 orange fumes of nitrous acid gas, the solution 

 strikes a deep blue with ammonia ; 2, as 

 Sulphuret, trimetric, dark-gray, H. 2 '5-3, 

 sp. gr. 57, or "Copper-glance" hexagonal, 

 dark-blue, sp. gr. 3-8, or " Indigo Copper" 

 dimetric, brass-yellow, sp. gr. 4-2, or " Copper- 

 pyrites," known from iron-pyrites by being 

 able to be cut by a knife ; 3, as Oxide, mono- 

 metric, red, brittle, H. 3'5-4, sp. gr. 5 - 99, or 

 " Bed-Copper ;" 4, as Silicate, rhombohedral, 

 emerald-green, transparent, H. 5, sp. gr. 3*278 

 or " Dioptase ;" 5, as Carbonate, H. 3'5-4, in 

 oblique prisms, azure, transparent, brittle, 

 sp. gr. 3-7, or " Blue-Malachite," massive, bright 

 green, sub-translucent or opaque, sp. gr. 3-9, or 

 " Green-Malachite ;" 6, as Sulphate, triclinic, 



