| Answer | Crossword Clue |
|---|---|
| gneissic | pertaining to gneiss (a type of rock) |
| breccial | pertaining to breccia (a type of rock) |
| geodic | pertaining to a geode (a type of rock) |
| sialic | pertaining to sial (a type of rock formation) |
| gneisses | GNEISS, a type of rock |
| diapiric | pertaining to diapir (a bend in a layer of rock) |
