31 Gallium (Ga)

atomic weight 69.72, melting point 30° C, density 5.90 g/cc


Gallium medal by Metallium, Inc. Photo used by permission.
Diameter 19 mm, 2.5 grams, 99.9% pure. $29 on 11/5/2006

Gallium has a melting point of 30°C (86°F), well below human normal body temperature. That means just holding this coin in your bare hand will cause it to melt. Because I live in Houston, where the temperature of my house could well go over 86 degrees in the summertime, I have to keep this coin in the fridge.

Because Gallium has such a low melting point, Metallium was able to fabricate this coin using a casting technique, rather than die-struck as their other coins have been to date. It had to be shipped using a 'cold pack' to keep it from melting during shipment.