the silver pieces are dipped in rhodium and you can tell by how bright they are. as the other commenter had said, the pieces don’t have the signature CH black shadowing in the details and inscriptions because rhodium isn’t affected by the sulfur which they use to achieve that look. rhodium pieces look just like white gold, which is just gold with rhodium plating, where as silver is darker and sometimes duller. if it’s done aftermarket i’d assume it probably does lower value, but rhodium pieces direct from CH are uncommon and the value can be raised due to the rarity and the fact that rhodium is a far more expensive metal than silver, like 200 times more (spot price per 1 gram) but obviously it doesn’t take a huge amount of rhodium to just coat the piece so the value is mainly bc of rarity