if i wear my platinum ring threaded on a white gold necklace (eg like a pendant) could that damage the platinum or white gold?
is the white gold strong enough?
Unless the necklace is very, very thin (like, less than a milimeter in width, especially if it''s some sort of a link chain), and the ring is very heavy, you should be fine. White gold is softer so it will suffer the damage, not the other way around - at least not under normal circumstances.
The platinum ring can wear away at the white gold ring because platinum is a stronger metal than gold. Because white gold is plated with rhodium to look white, a platinum ring will wear away the plating of a white gold ring faster than usual, revealing a yellowish tint and requiring the white gold ring to be re plated sooner and more frequently.