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Show 185 ANALYSIS OF THE TIN ORE OF TIMESCAL, SAN DIEGO COUNTY, CALIFORNIA. The tin mine of Timescal became famous by the continuous litigations it caused, not by the metal produced. No work was done for seventeen years, litigation preventing it. I was unable myself to visit the mine, hence can express no opinion as to the prospects, but received specimens of the peculiar ore from two persons, one in San Bernardino, the other in Los Angeles; the specimens resembled each other perfectly, and were said to represent the average ore. It is diffiealt to recognize in this black rock a tin ore; nobody would suspect the presence of tin; still chemical analysis reveals it, although the quantities, at least in the specimens at my disposition, are email. Luster, dull; streak, grayish; hardness = 3; specific gravity = 3.40. In the uniform black mass brighter particles of a crystalline structure are reoognizable. The ore contains no water of hydration, and is but with great difficulty attacked by acids, whereby some oxide of iron is obtained in solution. Fusing potassa decomposes the ore rapidly, and if the mass be treated with water a yellow powder, containing oxide of iron, silica, potassa, and antimonic oxide, remains insoluble, while tin is found in the alkaline solution. The former is easily decomposed by hydrochloric aoid. The quantitative analysis gave- Silica 39.70 Oxide of iron* 35.85 Alumina 5.01 Oxide of tin 3.52 Oxide of antimony 3.93 Lime 5.81 ir".::::;:;:::;:::::::^ * » Titanic acid traces. 98.19 ANALYSIS OF PARTZITE, OF BLIND SPRING DISTRICT, CALIFORNIA. This peculiar silver- ore is thus far known to occur only at one locality, the Blind Spring Mountains, near Benton, in Mono County, California. I visited myself the mine in which it used to be found in abundance, ( the Comanche lode;) but at present, with the deepening of the shaft, it becomes very rare, the sulphuretst predominating over the oxidized ores and carbonates. The color of the partzite varies from yellow ish- . green to black; no crystallization is perceptible; luster, dull; fracture, conchoidal; streak, gray to brown ; hardness= 3 j specific gravity = 5.324. Nitric acid dissolves it partially, with disengagement of red fumes, due to the presence of protoxide of iron in the ore becoming peroxodized. The quantitative analysis revealed the presence of copper, lead, iron, silver, and antimony. The latter element is present in the state of antimonic acid, as I have proved by treatment of the finely- pulverized ore with potash and addition of chloride of sodium. The ore has been previously analyzed by A. A rents,* who calculates the antimony as the oxide, and finds the specific gravity = 3.8, a number which is utterly impossible in consideration of the • composition, as antimonial ores have never less than 5.2 specific gravity. The result below given would correspond approximately to the general formula : S bo5f 4 Ro, 4 Ho, " but it is very doubtful whether this ore can be designated as a mineral species, as the necessary requisites are wanting. It is probably a mixture of antimoniate of iron and silver with the hydrated oxides of copper and lead. The great deviations in the composition of this ore are shown by the following comparison of the analysis made by Mr. A. Areata ( 2) and myself, ( 1.) ( 1.) ( 8.) Antimonio acid „ 34.03 47.65 Oxide of copper 18.39 32.11 Oxide of silver 3.28 6.12 Oxide of lead 23.51 2.01 Protoxide of iron 10.04 2.33 Water 10101.. 5350 988.. 5219 * A small portion of the iron is present as inaguecio oxide. t Argentiferous antimonial lead and copper sulphurets. X American Journal of Science and Arts, 1867. |
