Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/94

 In aggregated acicular crystals; opake; lustre silvery. From Allenheads and Aldstone moor.

Larger crystals of the same form: lustre adamantine. From the Teesdale mines.

Black acicular crystals; Fair hill, Flow-edge.

Capillary crystals; lustre silvery. On iron-stone. From Allenheads and Teesdale.

Phosphate of Lead.—Botryoidal, of a pale dirty green colour. Grass hill, Teesdale.

Of a siskin green colour, crystallized in small 6-sided prisms, terminated by 6 planed acuminations, forming clusters in light yellowish brown marly earth: from Surside mines, Netherdale, Yorkshire. This ore yields 60 per cent. of lead, and makes a beautiful green pigment.

The following ores of lead also occur; green, yellow, and white lead ore investing galena, from Allenheads and Aldstone moor: coherent earthy lead ore of a dirty white colour, without lustre, worked in considerable quantity at Grassfield mine near Nent head: lead ore of a whitish grey colour, resembling scales of mica, the white sill of the miners, from Allenheads, &c.: friable earthy lead ore of a dark reddish-brown colour, from Aldstone moor, &c.

Copper pyrites with galena from Cross gill, Aldstone moor.

Azure Copper ore.—In very small nodules imbedded in opake white heavy spar; found in small quantities at Wessinghope lead mine near Stanhope in Weardale in the great limestone.

Malachite.—Small quantities occur in the Dufton lead mine.