Why are there big rocks on this roof? [more inside]
posted by Tube on Jun 28, 2009 - 9 answers

Can anyone help me find a source for otoliths, or the tiny stones found in the inner ear? Preferably mammalian, ideally primate or even human (I imagine that last one may be ethically way to far, no offense intended). [more inside]
posted by buzzv on Feb 3, 2009 - 9 answers

How can I find places where it's legal to gather rocks? [more inside]
posted by agropyron on Oct 13, 2006 - 8 answers

How are semiprecious stones dyed? [more inside]
posted by cmyk on Apr 12, 2006 - 6 answers