224 IRON. small conchoidal; and some varieties are straight or curv ed foliated, with a fourfold cleavage. The fragments are indeterminate angular, and rather sharp-edged. It occurs unseparated, or in distinct concretions, which are occasionally so loose that they can be separated by the finger; also in straight and curved lamellar concre tions. The colour of the streak is black. It is intermediate between semi-hard and hard, and some varieties pass into hard. It is brittle. It is difficultly frangible, but by the action of the wea ther it readily becomes more easily frangible. It is heavy, inclining to uncommonly heavy. Specific gravity, Compact, 4.587,-5.283: Foliated, 5.400, UUmann, From Danemora, 4.93G4, La Mctherie. 4.094, Kir wan. It is highly magnetic, with polarity. / Chemical Characters. Before the blowpipe it becomes brown, and does not melt: it communicates to glass of borax a dark-green co lour. Constituent Parts. 1’eroxide of Iron, - 71.SO l'rotoxide of Iron, - 28.14 100.00 Berzelius. I)r 1 homson analysed a specimen of this ore from Greenland, and which he found to contain, besides the Iron, a small portion of Titanium.—Wern. Memoirs, vol. ii. part i. p. 55. C cog nos tic