|Dendritic crystals. |
Crystals of this shape generally come from precipitation out of a solution. These are coated with a layer of oxide (all rare earths are reactive to some degree or another with air). It's now stored under mineral oil to prevent further oxidation. "George" reports: "Samarium oxide is particularly annoying because it crumbles off the sample and is like fingerprinting dust, it's so fine."
Source: George (not 007) Lazenby
Contributor: George (not 007) Lazenby
Acquired: 20 November, 2002