Rip Off Britain, Today - Commemerative Coins

[barry1010]

Did anyone see this? I have no interest in coin collecting but am puzzled by the first report in this segment.
Chap took his 'gold' coin to a jewellers to sell, along with the certificate. Jeweller noticed there was a different colour showing through the yellow gold and suggested it was base metal plated with a thin coat of gold. Certificate described it as 'gold', just gold.
Off it went for testing, and it was shown that it was 9ct gold throughout, yellow gold over white gold. Jeweller said he couldn't buy it as it wasn't gold and his buyers demanded gold.

Now the certificate did seem a bit dodgy not stating that it was yellow 9ct gold over 9ct white gold, or even that it was 9ct gold but it didn't claim to be anything that it wasn't, as far as I could tell.
But surely 9ct gold has a value regardless of whether it is white or yellow. I thought the jeweller was more concerned about bigging up the reputation of his business than helping the seller.

My question is - does plating white gold with yellow gold make an item worthless, or even worth less? Was the description on the certificate misleading?

[gingejbee]

I would have thought that a certificate of authenticity supplied by a reputable company would have specified the purity of the "gold"...after all, 9 carat gold is just over a third actual gold, the remainder being probably silver and copper.

[barry1010]

I agree about that, ginge, but 9ct gold still has a value and has to be hallmarked. Thinking about that, are gold coins hallmarked?