Plating is used to cover an inferior base metal, to make a product hypo-allergenic, or to protect a precious base metal. Many pieces of costume jewelry use an inferior base metal which neither lasts long or retains it's shape. Some jewelry base metals produce allergic reactions with the wearer. Even some of the higher end base metals require protection if only for the fact that they are softer metals.
White gold got it's start with plating from both the allergen and soft metal aspect. 14K white gold is only 58.3% gold at it's best. In its early production, white gold was made from yellow gold and nickel. It's now made by adding manganese or Palladium to yellow gold. Of course, if the yellow gold used is lower or higher than 14K, the white gold rating is similar. 18K white gold has 75% yellow gold as it's base.
The early use of nickel as the combining metal in white gold resulted in the first use of Rhodium plating. So many folks were allergic to nickel that they were having to avoid white gold altogether. Jewelers opted to use Rhodium as it not only provided a hard protective surface but, it helped with the allergy problems of the nickel. Even though today's white gold is made with manganese or Palladium, ALL white gold is STILL plated with Rhodium.
Rhodium worked so well with the white gold that it was carried over into the bridge- or fashion-jewelry arena. Costume jewelry also uses a "white" plate but it is an imitation rhodium made of copper, tin, zinc, and/or nickel. Not good for those with metal allergies.
Not really. There are many kinds of plating, ways to plate, and different thicknesses of plating. Fashion jewelry rarely uses the lesser quality materials. Seldom do you find any plating other than 14K gold, sterling silver, or Rhodium.
While plating has been around since the early 1800s, there are several different methods. Two of the most common are:
Think of the two this way. Slap your hands together like you're clapping. That's like galvanic plating. Now, put your hands in front of you and lace your fingers together as if making a step to help someone step up on a ledge. That's what ionic plating is like. AND, that's why most of our jewelry is now ionic plated.
Platings are generally done in microns (1/1000 of an inch). While most plate to 2 microns, our jewelry is plated at 3 or 4 microns.
We'll identify all items as to their base metal, plating method, and plating material. With that information, you can make the right decision in every case. There's no better way to get the most product for your money than to be the most informed about the product.