| Tresayes Quarry | |
| Map: | Cornwall |
| Location: | near Roche |
| Nearest City: | Truro |
| Coordinates: | 50.3921°N -4.8222°W |
| Grid Ref Uk: | SW 995585 |
| Operator: | Cornwall Wildlife Trust |
Tresayes Quarry is a nature reserve near Roche in Cornwall.It is also a geological nature reserve of Cornwall Wildlife Trust and is designated as a (non-statutory) County Geology Site.[1] The entrance to the reserve has a small car park with a gate at ///leader.tango.speakers
Pegmatites can be found here. They are formed by the action of molten magma rising from deep within the Earth's crust. Associated with the pegmatites, rare elements, such as niobium, cerium and beryllium also occur.[2]
When the quarry was first opened in the late 19th Century, it was a source of pure feldspar which was used in the glass making industry. The site was known locally as the Glass Mine or Polpuff.[3] It closed for several years but reopened in 1917, during the First World War, to provide feldspar for electrical porcelain with at least 50 bal maidens separating the feldspar.[4]
Since 2011 the quarry has been an EarthCache, visited by the geocaching community.[5]