| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| Of the 3 major types of rocks, slate belongs to this one | metamorphic | $600 | DJ | GEOLOGY | 1996-02-19 | #2646 | |
| A rock that's "gneiss" falls into this class | metamorphic | $1,000 | DJ | GEOLOGY | 1988-10-10 | #941 | |
| The 3 classes of rocks are igneous, sedimentary & these, which used to be the other two | metamorphic | $600 | DJ | ROCKS & MINERALS | 1985-06-05 | #193 |