Sciencemadness Discussion Board

calcium granules

itchyfruit - 10-7-2009 at 02:37

What colour should calcium granules be ? mine are very dark pretty much black. I've tried cleaning some up in isopropanol but no joy is this an oxide layer or is calcium this colour,i thought it was white!!

bfesser - 10-7-2009 at 05:41

Calcium is shiny and silvery when fresh. It quickly oxidizes and forms a layer of oxide, nitride, etc. quickly when exposed to air.

[Edited on 7/10/09 by bfesser]

itchyfruit - 10-7-2009 at 06:52

Thanks, i guess i'll just have to get a ampouled sample for my element collection.

JohnWW - 10-7-2009 at 07:17

That is correct, Bfesser. The stuff should be stored under either light mineral oil in a well-stoppered vessel or very pure argon, like sodium and other alkali metals, so that air and water vapor cannot get at it. It is similarly obtained by the electrolysis of a molten halide salt under argon.