White gold is a mixture of some silver, nickel or zinc combined with a little copper to give the alloy a yellowish color and this alloy is added to gold to make white gold. Sterling silver is practically all silver.
Cagsil, gold is not 100% gold unless it is 24 KT gold. Anything less will be gold mixed with other metals such as copper, silver, zinc, and nickel. Sterling silver is about 93% silver and the other 3% is usually copper.
White gold alloy used to be mostly a mix of gold and nickel, however some people are allergic to the mix (the reaction is called "nickel itch" actually).
So typically, if you bought your ring within the last decade it has less nickel in it to cut down on nickel itch and a certain amount of brittleness that a nickel heavy alloy is susceptible to. The newer alloys have caused complaints that they are too yellowy. As a result white gold is constantly being tinkered with to find a brighter whiter white (like light-bulbs!)
Rhodium is actually in the platinum family, which is where it gets its white color from. But rhodium as a metal is too brittle to work with, however it works very well with electroplating, which is what your jeweler did to make it top white.
Gold is very mallable, it has to be mixed with a metal to add strength. However, gold is yellow but mixed with other alloys (metals) it turns white, but not a bright white. Rhodium plating is a process that only takes a few minutes. It's a liquid solution and many refer to it as a dip. But, it works like electrolysis and it makes the ring shiny. Available in the USA 10k 14k 18k platinum- hypo allgernic
Now, I know I'm going to get a lot of flak for this, but I need to ask this question. Is the NBA and society being a bunch of hypocrites for wanting Donald Sterling to be punished for what he said? I mean...