What is gypsum? Gypsum is hydrous calcium sulfate (CaSO4*2H2O) It is in the sulfate group of minerals. It has a hardness of 1.5-2 and a specific gravity of 2.3-2.4
Gypsum is found in small quantities everywhere in the state, and is especially common in caves in rocks of the lower Mississippian Period.
When was it deposited? Although it is found in Paleozoic rocks, it was mostly deposited by secondary replacement, when water seeps through the rocks picking up minerals in one place and depositing them in another. In Tennessee caves, this is continuing today.
| Quaternary |
| Tertiary |
| Cretaceous |
| Jurassic |
| Triassic |
| Permian |
| Pennsylvanian |
| Mississippian |
| Devonian |
| Silurian |
| Ordovician |
| Cambrian |
| Proterozoic |
How is it mined and used? Gypsum is primarily used to make wallboard. It is also an ingredient in cement.