Although not terribly rare, germanium is ten times more expensive than silver due to the expense of getting it to 99.999% purity, as in this sample (which happens to be the most commercially available grade). The pieces resemble broken glass in shape but have a wonderful yellow-green tinge. Some of the surfaces have been polished and exhibit thin film interference effects so that the reflected light appears iridiscent. A truly stunning element that will make others want to get some for themselves!

CAS 7440-56-4