| Collected from: |
Hemmerdon Ball, Plympton, Devon |
| Date: |
June 2004 |
| Description: |
Hemmerdon Ball is formed by a cupola of the Dartmoor granite extending south west towards Plymouth. The open cast mining operation was last active in the early 1940s primarily to expolit the tungsten mineralisation for the war effort. The mine exploits a mineral stockworks of quartz veins carrying principally wolframite and cassiterite in greisenised granite (granite chemically weathered by hydrothermal activity into a quatrz-muscovite sand from which most of the feldspar has been kaolinised and washed out). This is a classic exposure of this feature and is a designated SSSI and only open by prior arrangement. |
| Wolfram vein |  |
Index of other featured fossil and mineral samples