Platinum is produced on a small scale as a by-product in alluvial gold mining on the Vatana River, near the village of Ambia, in the Vatomandry district. Traces of the metal have also been found in auriferous gravels in the regions of Fenerive, Marolambo, and Vandrozo, over an area extending along the eastern side of the island for a length of about 450 miles. The platinum is apparently derived from the decomposition of pegmatite. It is rarely found pure, being usually coated with iron oxide, and strongly magnetic, a property which is utilized in the process of separation from the gold[[63]].
NORTH AMERICA
Mexico
Platinum has been shown to exist in the states of Guerrero and Hidalgo in deposits of ferrous clays, which are of undoubted sedimentary origin, and are apparently laterites. The metal exists in a very finely disseminated state, invisible to the naked eye[[64]].
United States
At the beginning of the war there was a considerable shortage of platinum in the country, caused partly by the falling-off of the imports, and in part owing to the increased demand in connexion with munition manufacture.
California is the principal producer of crude platinum, and in 1917 this State supplied 460 oz. out of the total output of 605 oz.; with the exception of a few ounces from the State of Washington, Alaska and Oregon provided the balance.
A considerable quantity of foreign crude and manufactured platinum is imported annually, as shown in the following tables:
| Imports of Manufactured Platinum into the United States | ||||||||
|---|---|---|---|---|---|---|---|---|
| (In troy oz.) | ||||||||
| 1912. | 1913. | 1914. | 1915. | 1916. | 1917. | 1918. | ||
| From British countries: | ||||||||
| Canada | 777 | 582 | 55 | 139 | 511 | 332 | 253 | |
| United Kingdom | 19,169 | 16,595 | 6,476 | 7,692 | 9,513 | 3,195 | 357 | |
| Other British countries | 4 | 5 | 25 | |||||
| Total, British countries | 19,950 | 17,177 | 6,531 | 7,831 | 9,569 | 3,527 | 635 | |
| From foreign countries: | ||||||||
| France | 25,723 | 24,519 | 16,570 | 3,480 | 3,395 | 2,507 | 814 | |
| Germany | 22,673 | 29,075 | 30,015 | 2,350 | 10 | |||
| Netherlands | 159 | |||||||
| Norway | 258 | 120 | ||||||
| Russia (European) | 815 | |||||||
| Colombia | 480 | 207 | 1,665 | |||||
| Other foreign countries | 63 | 512 | 57 | 3 | ||||
| Total, foreign countries | 48,396 | 53,594 | 47,658 | 6,373 | 4,076 | 2,891 | 2,482 | |
| Grand total, oz. | 68,346 | 70,771 | 54,189 | 14,204 | 13,645 | 6,418 | 3,117 | |
| Imports of Crude Platinum into United States | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| (In troy oz.) | |||||||||
| 1911[[N]]. | 1912. | 1913. | 1914. | 1915. | 1916. | 1917. | 1918. | ||
| From British countries: | |||||||||
| Canada | 554 | 45 | 314 | 535 | 139 | 91 | 25 | 76 | |
| United Kingdom | 28,153 | 19,951 | 8,368 | 7,084 | 6,805 | 36,703 | 1,561 | 1,073 | |
| Other British possessions | 7 | 5 | |||||||
| Total, British countries | 28,707 | 20,003 | 8,682 | 7,619 | 6,949 | 36,794 | 1,586 | 1,149 | |
| From foreign countries: | |||||||||
| France | 44,964 | 10,178 | 7,284 | 4,921 | 3,507 | 13,014 | 52 | 166 | |
| Germany | 37,041 | 15,335 | 23,345 | 15,105 | 2,366 | ||||
| Norway | 200 | 442 | 285 | 302 | |||||
| Panama | 160 | 105 | 92 | 12 | 372 | ||||
| Brazil | 118 | 103 | 27 | ||||||
| Chile | 9 | 766 | 3 | ||||||
| Colombia | 5,503 | 6,627 | 10,461 | 12,387 | 13,121 | 25,588 | 21,071 | 25,365 | |
| Other foreign countries | 17 | 13 | 1 | 103 | 99 | 21,663 | |||
| Total, foreign countries | 87,525 | 32,162 | 41,290 | 33,015 | 19,385 | 39,217 | 22,103 | 47,596 | |
| Grand total, oz. | 116,232 | 52,165 | 49,972 | 40,634 | 26,334 | 76,011 | 23,689 | 48,745 | |