Josephinite, a new nickel-iron

H~story.-Several m.ont~ls ago Pr~f. F. W. Ol.arke submitted to me for exammatlOn a qnantlty of magnetIc pebbles which were sent to this office by Mr. W m. H. Hampton of Portland, Oregon, and by subsequent corresponden:e with this gentleman he obtained a larger amount with full lIberty to publish the results anived at in the laboratory. In the spring of18Vl Mr. Hampton discovered these pebbles in large quantities in the placer gravel of a stream in Josephine and J ackson Counties~ Ol'egon, which border on the south of Douglas Co. where the nickel silicate* described by Prof. Clarke occurs. He analyzed with reference to nickel and iron au average sample of twenty pounds of the wash gravel from the placel' diggings, and found that the metallic portion gave GO'3 per ceut nickel and :36'7 per cent iron. From the natlll'e of the gangue or stony portion MI'. Hampton concluded that these waterWOl'll pebbles and bowlders-for some pieces weighed over one hundred pOllnds--" came from an eruptive dike somewhel'e ill the vicinity." The locality of this dike was not at that time ascertained. PAysical OAaraciers.The pebbles are irregular in shape but approximate the form of ellipsoids. Their smooth surfaces, polished by the action of water, are colored in general greenish black, interrupted b'y bright areas of the grayish white alloy of nickel and iron. The former portions consist of siliceous matter and when cut by a knife yield a dull and light gray powder, but broken fragments show greenish yellow and deep green colors and resinous luster resembling noble serpentine. -With this is associated in some pebbles a silicate whose hardness is between 5 and 6. It is compact and on the fresh fracture exhibits a light brown colol' and vitreous luster, while exposed sudaces are reddened by ferric oxide. The textlU'e of the metallic portion as it appears on fracture is granulal·. The metal is gray, malleable and sectile with hardness abont 5. The speciJic gmvity of one lot containing forty-two pebbles was taken in a pycnometer at a temperature of 22° C. These pebbles ranged in weight from 0'3159 to 1'64407 grams and were about the dimensions of a pea. The largest pebble in my possession weighed 40'215,17 grams, and the specific gravity of this was made by suspending it from a silk Jibet'. Two determinations fnrnished a mean specific gravity of 6'204.