Show sample as: 72-frame QuickTime VR or 360-frame QuickTime movie loop.    My periodic table poster is now available! Experimental solar cell. An experimental solar cell made with ruthenium at Imperial College. I don't know if they have fully thought through the ramifications of ruthenium being one of the more expensive of the metals. Source: Max Whitby of RGB Contributor: Max Whitby of RGB Acquired: 2 April, 2009 Text Updated: 3 April, 2009 Price: Donated Size: 1.5" Purity: <5%