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Manual of the natural history, geology, and physics of Greenland, and the neighboring regions; prepared for the use of the Arctic Expedition of 1875, ... for the use of the expedition. Publish
Manual of the natural history geology and physics of Greenland and the neighboring regions prepared for the use of the Arctic Expedition of 1875 for the use of the expedition Publish Author:Great Britain. Admiralty This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1875 Excerpt: ...variety. The other bed is separated from the former by an elevation of the underlying gneiss, and has a very different appearance. The sno... more »w-white and greyish-white colour is changed gradually into reddish-white, and passes, in proportion to tho quantity of imbedded metallic substances, into orange-yellow and brownish-red. We find in the reddish-white variety quartz crystals and particles of flesh-red felspar; in the orange-yellow and brownish-red varieties sparry-iron-ore, iron-pyrites, copper-pyrites, and galena occur in great abundance. Sparry-iron-ore occurs massive and in rhomboidal crystals, accumulated in groups of considerable size. Its colour is always dark blackish-brown, and the surface of the crystals partly tarnished, partly decomposed. I found some of the crystals hollow, and some filled with particles of common ironpyrites. Iron-pyrites occurs generally massive, rarely crystallised in cubes and dodecahedrons. Copper-pyrites occurs only disseminated in galena. The galena of this place has the peculiar property of melting calmly before the blowpipe into a globule, without the least decrepitation. Some fragments are covered with a yellowish-white and greenish-white coating, which, when held to a candle, burns with a blue flame and a sulphurous smell. This kind of galena presents some properties of native lead, as the sulphur appears to be elicited, and the ore reduced, by the action of the sea-water or the atmospheric air. Galena occurs here disseminated, massive, but rarely crystallised iu perfect cubes, and in cubes truncated on the angles and edges. This variety of cryolite (I may perhaps call it, in a geological view, metalliferous cryolite) was not known in Europe before I visited the coast of Greenland; because, owing to its decomposed stat...« less