Coffey Quarry, Stone Mountain-Lithonia Mining District, DeKalb County, Georgia, USAi
| Regional Level Types | |
|---|---|
| Coffey Quarry | Quarry |
| Stone Mountain-Lithonia Mining District | Mining District |
| DeKalb County | County |
| Georgia | State |
| USA | Country |
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Latitude & Longitude (WGS84):
33° 44' 47'' North , 84° 6' 59'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Redan | 33,015 (2011) | 1.4km |
| Lithonia | 2,022 (2017) | 3.9km |
| Stonecrest | 50,000 (2017) | 4.5km |
| Pine Mountain | 1,210 (2010) | 7.8km |
| Stone Mountain | 6,109 (2017) | 8.5km |
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 |
|---|---|---|
| Georgia Mineral Society, Inc. | Norcross, Georgia | 23km |
| Cobb County Gem and Mineral Society | Marietta, Georgia | 46km |
Mr. G. Coffey owns about five acres of exposed rock about two and one-half miles north northwest of Lithonia. Three quarry openings have been made, the largest of which has a worked face one hundred feet long and three feet high.
The rock is a strongly foliated biotite-rich granite of the Stone Mountain type. It is uniform in texture and composition except for thin muscovite-rich lenses with scattered garnets similar to those found at Stone Mountain. Several coarse-grained pegmatites composed of microcline, quartz, muscovite and biotite have intruded the rock.
The flowage foliation varies in strike from Nl0°W to N25°W and dips from 15° to 25°W. Joints are very rare. The grain of the rock trends N-S.
The rock is a strongly foliated biotite-rich granite of the Stone Mountain type. It is uniform in texture and composition except for thin muscovite-rich lenses with scattered garnets similar to those found at Stone Mountain. Several coarse-grained pegmatites composed of microcline, quartz, muscovite and biotite have intruded the rock.
The flowage foliation varies in strike from Nl0°W to N25°W and dips from 15° to 25°W. Joints are very rare. The grain of the rock trends N-S.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
3 valid minerals.
Rock Types Recorded
Note: data is currently VERY limited. Please bear with us while we work towards adding this information!
Select Rock List Type
Alphabetical List Tree DiagramDetailed Mineral List:
| ⓘ 'Biotite' Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| ⓘ 'Garnet Group' Formula: X3Z2(SiO4)3 |
| ⓘ Microcline Formula: K(AlSi3O8) |
| ⓘ Muscovite Formula: KAl2(AlSi3O10)(OH)2 |
| ⓘ Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 4 - Oxides and Hydroxides | |||
|---|---|---|---|
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 9 - Silicates | |||
| ⓘ | Muscovite | 9.EC.15 | KAl2(AlSi3O10)(OH)2 |
| ⓘ | Microcline | 9.FA.30 | K(AlSi3O8) |
| Unclassified | |||
| ⓘ | 'Biotite' | - | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| ⓘ | 'Garnet Group' | - | X3Z2(SiO4)3 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| H | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| O | Oxygen | |
| O | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| O | ⓘ Microcline | K(AlSi3O8) |
| O | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Garnet Group | X3Z2(SiO4)3 |
| F | Fluorine | |
| F | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Mg | Magnesium | |
| Mg | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Al | Aluminium | |
| Al | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Al | ⓘ Microcline | K(AlSi3O8) |
| Al | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Si | Silicon | |
| Si | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Si | ⓘ Microcline | K(AlSi3O8) |
| Si | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Garnet Group | X3Z2(SiO4)3 |
| K | Potassium | |
| K | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| K | ⓘ Microcline | K(AlSi3O8) |
| K | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Ti | Titanium | |
| Ti | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
| Fe | Iron | |
| Fe | ⓘ Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- PedmontiaAccretionary Complex
- Piedmontia DomainDomain
USA
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