| Answer | Crossword Clue |
|---|---|
| nephelinite | A fine-grained basaltic rock containing nepheline in place of plagioclase feldspar |
| porphyry | A hard igneous rock containing crystals, usually of feldspar, in a fine-grained, typically reddish groundmass |
| porphyries | A hard igneous rock containing crystals, usually of feldspar, in a fine-grained, typically reddish groundmass |
| tinguaite | a fine-grained igneous rock composed essentially of feldspar, nepheline and aegirine |
| tinguaites | TINGUAITE, a fine-grained igneous rock composed essentially of feldspar, nepheline and aegirine |
