Platinum

[EcclesCake]

I always thought platinum was a very stable metal and didn't react to other substances on the whole.

For some strange reason my finger has become discoloured underneath my platinum rings. I can think of nothing out of the ordinary I have handled today and I have never had a problem before.

Any ideas?

[DTCwordfan]

what colour is the staining, black?

[EcclesCake]

Yep

[DTCwordfan]

sounds like you have had a little bit of oxidation occurring - quite rare actually as Pt is one of the most inert metals. Had your hands near any acids, even lemon juice (citric acid), as that can cause the oxidation process to PtO2 (known as "Adams catalyst").

Often colouring in gold is from the other chemicals in the alloy (lower K (caret) being higher risk)......your platinum bands aren't a PT alloy are they as that is an alternative....

[DTCwordfan]

most "commercial" rings are 85% Platinum; copper, cobalt - the common additions, and palladium, ruthenium and iridium combinations being also added.

[DTCwordfan]

could be, methyl.....

[EcclesCake]

I handle citric and acetic acid on a regular basis yet I've never encountered discolouration like this before.

The only 'unusual' item I've handled today is a pomegranate, not that I recall any issues in the past.

My rings are old and well worn, I've never experienced such a reaction before.

Perhaps I just need a wash ;-)

[DTCwordfan]

lol - coal dust?!

Pomegranates are acidic (ph 5-5.5) but not as strong as say lemon or lime juice.

[EcclesCake]

I'll have a good wash, take 600mg Ibuprofen and monitor the situation.

As this is in science I will take hourly obs......and then draw a graph.

[DTCwordfan]

put good lingerie on and the doctor will lose it!