Iridium was discovered in 1803 by British scientist Smithson Tennant in London, England along with osmium in the dark-coloured residue of dissolving crude platinum in aqua regia (a mixture of hydrochloric and nitric acid). The element was named after the Greek word for rainbow (ίρις, iris; iridium means "of rainbows") because many of its salts are strongly coloured. (wikipedia quote)
And yes to your other question, but I'm not a scientist or chemical/physical property expert on this, so here you go.
http://en.wikipedia.org/wiki/MetallicHere's a pic of some iridium sunglasses