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| | Arsenide ore from Silver Centre, Ontario |
 | | The source locality for this sample is in South Lorrain township, an area of the Cobalt district which sported a number of significant mines (Keeley, Lorrain, etc), although the township may have provided just 3% of the silver from the prolific mining region (Petruk, 1971; Anderson, 1990). |
 | | The 1903 discovery of high-grade silver ore in the Cobalt district was the precursor to a prospecting and mining boom of rare scope. |
 | | The veins vary from roughly 10 cm to 1 km in length, 10 cm to 120 m in vertical extent and from hairline fracture to 1.2 m in thickness (Petruk, 1971). |
| www.turnstone.ca /arsenide.htm (975 words) |
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