Yes they are made of solid 18 kt gold. However the fading phenomenon is quite curious. TPFers exposed several hypotheses about it; but I tend to think that the fading may be due to something else.
First the copper rate in Cartier RG is certainly lower than average RG jewelry everywhere else (I’d say 15% max against 20% in traditional rose gold and 25% in red gold).
And second, the sterling silver rate may be higher in Cartier RG jewelry too. I tend to think the fading may come from a higher rate of sterling silver in the final alloy. Sterling silver being well-known for its natural oxydation; it could make sense.
But it’s just my hypothesis.![]()
They use sterling silver in their alloy yet charge just as much for the solid YG?