| | |   Brookite. I actually bought this crystal by mistake: I was going through mindat.org looking up the name of every single mineral that contains thorium, then searching on eBay to see if I could buy one of them.  (I needed more pictures of thorium crystals to use for the short-lived radioactive elements that appear in the thorium decay chain.)  For some reason I got confused and bough this one too: It's titanium dioxide with no hint of anything radioactive.  But it's pretty just the same!
 This is officially described as Brookite and smoky quartz from Magnet Cove.
 Source: eBay seller crystaldigger
 Contributor: Theodore Gray
 Acquired: 20 September, 2005
 Price: $29
 Size: 2.2"
 Composition: TiO2
 | 
 |   | 
 |