norm8332 wrote:If it were silver you think it would be tarnished by now?
I don't know for sure what it is these carts used for contact plating but I do know it is much tougher than HASL yet doesn't cause any problems, just like gold. If you rub the contacts with a white eraser, they come back almost as clean and shiny as new. You can't do that with HASL.
For a long time I was puzzled with 'In The Chips' in particular because if it's not gold but doesn't wear and scratch like HASL, it's probably a much cheaper alternative to gold that can do just as good a job.
I suppose it would be a good question for a jeweler what metal can be used as part of a silver based alloy to prevent tarnishing.
See 'silver plating' here: http://www.sharrettsplating.com/industr ... troplating
A nickel undercoat can help to limit tarnish and prevent the formation of potentially harmful silver-copper intermetallics.