| Home |
| Rocks and Minerals |
| Shale |
| Hornfels |
| Diabase |
| Limonite |
| Greenstone |
| Rhyolite |
| Quartzite |
| Conglomerate |
| Limestone |
| Sandstone |
| Calcite |
| Quartz |
Limestone |
| The most common rock in the Frederick Valley, limestone can be identified by its gray color. This sedimentary rock is used throughout the county for many uses. |
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