Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/95



Iron Pyrites.—Massive and Crystallized.

Carbonate of Iron.—Pearlspar; massive, mammellated, and in small lenticular crystals, yellowish white, light and dark brown, and black from decomposition; too common in all the mines.

Blende.—Black and brown, amorphous and crystallized; in all the mines.

Reddish brown, in small crystals, scattered over quartz and fluor spar, and in minute crystals upon stalactitical brown quartz; from Aldstone moor.

Blood-red irregular crystals on limestone, with crystals of purple gluor; from Aldstone moor.

Calamine is worked in old Hagg's cross vein near Nent head. One variety is of a yellowish grey colour; conchoidal in fracture, and in a slight degree transparent: another is snow white and perfectly opake.

Ore of Zinc.—In thin white opake layers or incrustations from Allenheads.

''Carbonate of Lime. Calcareour Spar''.—In acute and obtuse pyramids, (the dog tooth and nail head spar) from Aldstone moor.

In dodecahedron's on pearl spar (Sowerby, t. 42) from Aldstone.

In 6-sided highly transparent prisms terminated by 6-sided pyramids, called Tyne bottom spar; from the Tyne bottom limestone on Aldstone moor.

In pale straw coloured 3-sided pyramids. This delicate fossil has been observed in a vein opposite New-house in Weardale.