Glassy Carbon
Image: <a href="//commons.wikimedia.org/wiki/User:Alchemist-hp" title="User:Alchemist-hp">Alchemist-hp</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Alchemist-hp" title="User talk:Alchemist-hp"><span class="signature-talk">talk</span></a>) (<a rel="nofollow" class="external text" href="http://www.pse-mendelejew.de">www.pse-mendelejew.de</a>) (FAL)
Description
A large, irregularly shaped, black material with a highly reflective, glassy surface showing prominent conchoidal fractures, displayed next to a small, dark graphite cube for comparison.
Geological Context
Glassy carbon is a synthetic, non-graphitizing form of carbon produced by the pyrolysis of carbon-rich polymers in an inert atmosphere at high temperatures. It does not occur naturally in geological settings.
