| Answer | % Correct |
|---|---|
| Basalt | 86%
|
| Limestone | 76%
|
| Flint | 73%
|
| Chalk | 70%
|
| Marble | 70%
|
| Obsidian | 65%
|
| Slate | 64%
|
| Quartzite | 60%
|
| Pumice | 56%
|
| Bauxite | 53%
|
| Shale | 52%
|
| Feldspar | 44%
|
| Gneiss | 33%
|
| Breccia | 13%
|
| Trachyte | 13%
|
| Porphyry | 11%
|
| Scoria | 9%
|