Europium is the most reactive of the lanthanides, quickly reacting with both oxygen and water. Europium rapidly oxidises in air and as the corrosion products spall off, exposing fresh metal, it is soon entirely consumed, leaving behind a pile of oxides and hydroxide. For this reason it is rarely seen in a recognisably metallic form.
The rare earth metals are not as rare as the name implies and europium is almost as common as tin. Unlike tin, however, there are no concentrated ores of europium, indeed there are no minerals containing europium as a major constituent. Instead it occurs mixed with the other lanthanide metals in concentrations ranging from 0.04% to 0.89% europium. Worldwide production of the pure metal is only around 100 tonnes a year.
The sample here consists of a solid cluster of europium crystals grown under vacuum and mounted in an argon filled sealed quartz dome. The cluster has a brassy gold colour, with some darker colours around the base (due to reactions with the glue used to mount it). It has a high metallic lustre and none of the dark, powdery corrosion products seen with many europium samples.
sealed quartz dome, under argon
size: dome 76mm H x 50mm D
sample size: ~50mm x 40mm
sample weight: 98 grams
Price: £650 ex. shipping