It generally contains ſome alloy of iron.

§ 194.

CUPRUM (copper), mineralized by ſulphur, and a ſmall proportion of iron.

Cronstedt Min. § 198, b. Minera cupri lazurea.

By a ſmall proportion of iron, I mean leſs than the weight of the copper; by a large proportion, more. This contains from 40 to 50 per cent. of copper.

§ 195.

CUPRUM (copper), mineralized by ſulphur, and a large proportion of iron. Pyritical.

Cronstedt Min. § 198. Pyrites Cupri.

The quantity of copper varies greatly, but ſeldom exceeds ⁴⁰⁄₁₀₀.

§ 196.