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British Mineralogy
Sulphuret of Lead; Galæna
- Class 3. Metals.
- Ord. 1. Homogeneous.
- Gen. 5. Lead.
- Spec. 7. Sulphuret of Lead.
- Div. 1. Crystallized.
- Syn.
- Galéne, Sulphure de plomb. De Born, v. 2. 354.
- Bleiglanz. Emmerl. v. 2. 369.
- Sulphuret of lead. Bab. 166.
- Lead mineralized by sulphur, compact galæna. Kirw. v. 2. 216.
- Plomb sulphuré. Haüy, v. 3. 436. 7.
- Plumbum galæna. Lynn. Syst. ed. 12. v. 3. 133.
This is the commonest lead ore, and is found in Derbyshire and Cumberland; also in Wales, Scotland, and Cornwall. It seldom occurs truly amorphous. The present specimen came from Derbyshire, and is valuable from having the primitive cubic crystals so distinct. They are somewhat brighter than manufactured lead, either outwardly or in the fracture, which rather more resembles manufactured lead fresh cut. Some varities are brighter than others; which is said to be owing to their containing more silver. Some varities have a diverting striated fracture. This ore holds lead in the metallic state. Before the blowpipe on charcoal it decrepitates, but melts easily with a sulphureous smell, part sinking into the charcoal. If alternately heated and cooled, it will at last vanish, and leave its silver, if it contains any. Berg. 493.—Spec. grav. 7,587. Brisson.
