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Tresayes Quarry (Polpuff Quarry), Trezaise (Tresayes), Roche, Cornwall, England, UKi
| Regional Level Types | |
|---|---|
| Tresayes Quarry (Polpuff Quarry) | Quarry |
| Trezaise (Tresayes) | Hamlet |
| Roche | Civil Parish |
| Cornwall | County |
| England | Constituent Country |
| UK | Country |
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Latitude & Longitude (WGS84):
50° 23' 34'' North , 4° 49' 15'' West
Latitude & Longitude (decimal):
UK National Grid Reference:
SW993590
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Roche | 2,517(2017) | 1.9km |
| Bugle | 2,873(2017) | 2.0km |
| Nanpean | 2,563(2017) | 4.3km |
| Saint Dennis | 2,206(2016) | 4.5km |
| Luxulian | 388(2017) | 5.5km |
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
Local clubs are the best way to get access to collecting localities
| Club | Location | Distance |
|---|---|---|
| British Micromount Society, Devon and Cornwall Branch Meetings | Liskeard, Cornwall | 26km |
Other/historical names associated with this locality:
Roche Felspar Works / Glass Mine
A disused quarry in a pegmatite known for its large feldspar crystals. First opened in the late 1870s, the Mining Journal records that production was hampered by severe winters on this exposed common. Early production was for pure feldspar which was used for making glass and the quarry was known locally as the glass mine. Although worked mainly as a quarry there are reputed to be underground workings.
The quarry was re-opened in 1917, during the First World War, to provide feldspar for electrical porcelain. It closed again shortly afterwards.
Cornwall Wildlife Trust manage the quarry. Until very recently, the dense vegetation combined with very damp conditions made it impossible to access the quarry. The quarry is managed on the remaining part of a 25 year lease from Goonvean China Clay Company.
After studying the exposure, when you return to your car, you will spot low grade ore samples in the unmade road. Only the purest feldspar was used and the rest treated as waste.
Select Mineral List Type
StandardDetailedGalleryStrunzChemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
2 valid minerals.
Detailed Mineral List:
| ⓘCordierite Formula:(Mg,Fe)2Al3(AlSi5O18) |
| ⓘOrthoclase Formula:K(AlSi3O8) |
| ⓘ'Pinite' |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 9 - Silicates | |||
|---|---|---|---|
| ⓘ | Cordierite | 9.CJ.10 | (Mg,Fe)2Al3(AlSi5O18) |
| ⓘ | Orthoclase | 9.FA.30 | K(AlSi3O8) |
| Unclassified | |||
| ⓘ | 'Pinite' | - | |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘCordierite | (Mg,Fe)2Al3(AlSi5O18) |
| O | ⓘOrthoclase | K(AlSi3O8) |
| Mg | Magnesium | |
| Mg | ⓘCordierite | (Mg,Fe)2Al3(AlSi5O18) |
| Al | Aluminium | |
| Al | ⓘCordierite | (Mg,Fe)2Al3(AlSi5O18) |
| Al | ⓘOrthoclase | K(AlSi3O8) |
| Si | Silicon | |
| Si | ⓘCordierite | (Mg,Fe)2Al3(AlSi5O18) |
| Si | ⓘOrthoclase | K(AlSi3O8) |
| K | Potassium | |
| K | ⓘOrthoclase | K(AlSi3O8) |
| Fe | Iron | |
| Fe | ⓘCordierite | (Mg,Fe)2Al3(AlSi5O18) |
Geochronology
| Geologic Time | Rocks, Minerals and Events | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Phanerozoic | ||||||||||||||||||||||
| Paleozoic | ||||||||||||||||||||||
| Permian | ||||||||||||||||||||||
| Guadalupian |
| |||||||||||||||||||||
| Cisuralian |
| |||||||||||||||||||||
Other Regions, Features and Areas containing this locality
British and Irish IslesGroup of Islands
Eurasian PlateTectonic Plate
- Rheno-Hercynian BeltOrogenic Belt
EuropeContinent
UK
- England
- Cornwall
- St Austell Mining DistrictMining District
- Devon and Cornwall metalliferous mining districtMining District
- Cornwall
This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, pleaseregister so you can add to our database. This locality information is for reference purposes only. You should never attempt tovisit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holdersfor access and that you are aware of all safety precautions necessary.
References
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Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are© OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 byJolyon Ralph and Ida Chau.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844.doi:10.2138/am-2024-9486.
Privacy Policy -Terms & Conditions -Contact Us / DMCA issues -Report a bug/vulnerabilityCurrent server date and time: February 20, 2026 06:13:28 Page updated: August 12, 2025 10:26:14
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are© OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 byJolyon Ralph and Ida Chau.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844.doi:10.2138/am-2024-9486.
Privacy Policy -Terms & Conditions -Contact Us / DMCA issues -Report a bug/vulnerabilityCurrent server date and time: February 20, 2026 06:13:28 Page updated: August 12, 2025 10:26:14