MINERALOGY. 193 
fometiffies foufid decorhpofed or weathered^ 
and changed into ,a deep mountain blue, 
Sed. Cxciv. 
SECT. CXCVlIl. 
2* With fulphurated iron. Miner a cupri pyri- 
tacea : Yellow copper ore. Marcafitical 
copper ore, Pyrites cupri. 
This is various both in regard to colour, 
and in regard to the different proportion of 
each of the contained metals *, for inftance : 
a. Blackifh grey, inclining a little to yel- 
low, Pyrites cupri grifeus. 
Vf hen decayed or weathered, it is of 
a black colour ; is the richeff: of all the 
varieties of this kind of copper ore, 
yielding between 50 and 60 per cent, and 
is found in Spain and Germany. 
b. Reddilh yellow, or liver brown, with a 
blue coat, on the furface, Miner a cupri 
la%urea. 
This ore yields between 40 and 50 per 
cent, of copper, and is commonly faid 
to be blue, though it is as red when freili 
broke, as a rich copper regulus. 
r. 'Yellow ifh green. Pyrites cupriJiavo virP 
defcens. 
This is the moil common in the north 
part of Europe { and is, in regard to its 
texture, found 
1. Solid, and of a fliiiiing texture, from 
Ofcanberg, in the province of Dalarne. 
2. Steel-grained, of a dim texture, from 
the fame place, and Falun in Dalarne. 
3. Coarfe-grained, is of an uneven and 
fhining texture. It occurs in moil of 
O the 
