| Answer | Crossword Clue |
|---|---|
| tufas | porous limestone formed from calcium carbonate deposited by springs or the like |
| tufa | porous limestone formed from calcium carbonate deposited by springs or the like |
| tufaceous | porous limestone formed from calcium carbonate deposited by springs or the like |
| calctuff | porous limestone formed from calcium carbonate deposited by springs or the like |
| calctufa | porous limestone formed from calcium carbonate deposited by springs or the like |
| stalactites | A tapering structure hanging like an icicle from the roof of a cave, formed of calcium salts deposited by dripping water |
