Opalized Dinosaur Tooth- Fossils are normally formed when minerals fill the cellular spaces and crystallize. Opalized fossils, on the other hand, form when bits of silica gel settled into the cracks and fissures of the cellular spaces and form opal.... umm...seriously?! That's amazing!
= o - a 306 carat black opal some Australian dude spent 2 years chiseling out of rock with a dental drill. Hid it under his mattress for 12 years (of course) and it's now up for grabs in Vegas... for $3 mill.