@cakids - I found some different information,,,
White gold was originally developed to imitate platinum (a naturally white metal). White gold is usually an alloy containing about 75% gold and about 25% nickel and zinc. If stamped 18 karat, it would be 75% pure gold.
and
Rhodium is a chemical element with the symbol Rh and atomic number 45. It is an ultra-rare, silvery-white, hard, corrosion-resistant, and chemically inert
But you are correct in that Rhodium is used a lot in jewelry, but in comparison to silver, coper and even gold - it is a poor conductor
From the table of Conductivity...
- Silver’s conductivity is 106,
- OCC copper is around 102
- Copper is considered the reference at 100
- Gold is 65
- Rhodium is 38
- Beryllium Copper is 22 (commonly used for plug contacts)
- Platinum is 15
BTW - Conductivity is VERY important for contacts
Also - If the contacts of a plug are Gold or Rhodium plated, then a substrate plating is required, which normally has an even lower conductivity rating than the plating materials.
Regards