Here is a very large chalcedony bird's nest - actually, a geode shaped structure made up of agate-like banded chalcedony that has grown up in a circular ridge with a 2.3" deep pit inside with some squiggly stalactite-like formations sticking up. . The most notable feature of this specimen is that the chalcedony is highly fluorescent, lighting up a brilliant electric green color under shortwave fluorescent light. There is no damage.