Show sample as: 72-frame QuickTime VR or 360-frame QuickTime movie loop.    My periodic table poster is now available! Etched block. This is an interestingly etched block of high-purity aluminum, showing the crystal zones. It is a full bar of the material featured a few samples back in the form of a short slice. Source: Ethan Currens Contributor: Ethan Currens Acquired: 8 February, 2009 Text Updated: 8 February, 2009 Price: Trade Size: 8" Purity: 99.99%