In reply to:

biolith: rock formed by living creatures

...and another one that's interesting. I can think of fossils. They would be rocks formed by living creatures. And limestone? That comes largely from shells and remains of sea creatures, so would limestone be a form of biolith?

Edit: Now that I reconsider, perhaps coral reefs would be a better example of bioliths. Perhaps limestone takes too long to form to be considered a form of biolith.