(no subject)

[jinian]

Is there any scale for measuring how likely a metal or alloy is to make your skin turn odd colors? (Like copper turns most people green or blue, and some people even react to sterling silver.)

Comments

[marzipan-pig.livejournal.com]

I think it's the nickel that's also in silver jewelry that's the problem

hmm

it does seem like a list at leat of common metal allergens should be someplace; maybe a piercing place would provide something like that?

[jinian.livejournal.com]

Actually, sterling silver contains copper but not nickel. I'm not really interested in allergies (though it's something to think about, since what I'm planning is to sell jewelry), I want to know how likely it is that a piece is going to turn someone's wrist blue. I just can't figure out how to find research about it.

a couple of things

[roobug.livejournal.com]

One page has this to say about allergic reactions:

It occurs as moisture leaches chemicals or metal ions out of the jewelry material. Plated metal or jewelry composed of several metals are especially prone to causing allergic reactions due to an electrochemical reaction that happens between dissimilar metals in the presence of moisture. (www.reactivemetals.com)

And another (http://www.24carat.co.uk/cheapjewelleryturnsskinblack.html) says (in part):

if you were to study a graph of the properties of gold alloys, you would find that at about 75% gold, the alloy becomes practically inert to attack and corrosion by most chemicals, 18 karat just fails to reach to standard, whereas 18 carat is above the critical point.

not that this shows you a graph or a chart, darn it.

[barda.livejournal.com]

This is the way I understand things:

Most base metal alloys run a strong risk of discoloring and reacting with your skin. It’s hard to say anything for sure because the exact composition of the alloy can be hard to determine and can change form batch to batch depending on metal prices, which fluctuate daily. An individual’s own chemistry has a lot to do with it too.

Most people who are sensitive, are sensitive to nickel, how sensitive you are has a lot to do with how you react. A good rule of thumb is to steer clear of base metals and their alloys. The purer your metal the less likely people are to have a reaction to it. Sterling Sliver 92.5% pure silver, that 7.5% can be anything, if it’s nickel or copper your more likely to have a reaction. There is also a lot of silver on the market that has a much lower percentage of silver, “India silver” is usually around 70% silver, if there is less silver and more “other stuff” the likelihood of a reaction goes up. Anything that is Sterling Silver usually has 925 stamped on it somewhere.

Most people do well with gold or gold-fill (14/20 is most common, but 18/20 would be purer), Niobium and Titanium are also good, however they are hard to work and aren’t as shiny or “pretty” as gold and sliver.

I could be wrong, but this is how I learned it and this is what I taught in my wire work classes.