|Osmiridium (aka Iridosmine). |
These are very small granules of native (naturally occurring) osmium-iridium alloy. These two metals are often found combined this way, and because the alloy is actually in many ways more useful than either element on its own, the mixture is often used just as it's found, for example in the tips of expensive fountain pens. Don't be fooled by the picture: This stuff is about the size of fine sand, I've just got a really good macro lens.
Source: eBay seller entropydave
Contributor: Theodore Gray
Acquired: 15 February, 2006
Text Updated: 5 December, 2006