Enter a clue or pattern or both:
The Clue
Algae remains (9 letter answer)
The Answer
DIATOMITE
Tags
Notes
The answer DIATOMITE is so rare that it appears less than once every 2500 puzzles.
Definition
DIATOMITE as a noun:
1. (diatomaceous earth, diatomite, kieselguhr) = a light soil consisting of siliceous diatom remains and often used as a filtering material