oxidized platinum. Has any one heard of this or any other
durable processes that are black. Fascinated with faceting...
It seems likely that the black platinum could have been Pt/Pd alloy.
One day while I was soldering a platinum jump ring with another
platinum tag (Pt850, 15% palladium), using propane gas torch, the tag
(which was placed a bit away from the hottest zone) changed its color
into a sort of brownish-black. I could remove this by pollishing with
abrasive. Given that oxidized palladium exhibit multiple color change
around 600C, I guess I experiencede that by chance.
Maybe one can control the degree of oxidization and the color by
putting Pt/Pd alloyb into a klin?
Would love to hear more from expertise - I'm also interested in black
colouring of metals, especially those involve oxidization.