The first decision really comes down to color. When producing fine jewelry, the manufacturing process has some natural limitations. Out of the ground gold is naturally yellow and platinum is naturally white. Palladium is in the platinum family, its not as common of a metal used for fine jewelry but I do use it occasionally for a custom request. The color is more of a steel white. Most people will think its white gold or platinum. The cost of Palladium is slightly more than white gold.
When choosing yellow gold, I typically make either 14k or 18k. As the karat content gets higher, the outer surface becomes softer. Thus, the jewelry item is more prone to getting scratched on the surface. This means 14k is more durable than 18k. At 24k we consider the jewelry to be 100% gold. To explain further, 14k/24k means that 14k is 58% actual gold and the 42% becomes other yellow color natural alloys to make up the rest. And 18k is 75% yellow gold and 25% is yellow natural alloys. I do have some accent items on rings at 22k, but not as the main body of the ring.
To briefly explain the colors, to make rose gold we use copper to turn the color to rose tones. At 14k the rose gold is more reddish and at 18k the rose gold is more peachy. This has to do with a higher content of yellow and less of copper. When making white gold, we use the white alloys of iridium, cobalt, and palladium in certain percentages. It's all like making a soup in which we add certain percentages of each to achieve the best outcome possible. The main thing at the end of the day is the gold content is what it should be.
If someone knows the choice is going to be white metal. Then that leaves the option of white gold or platinum. When a ring is brand new, they will look the same. As the ring wears, the rhodium plating on the white gold ring will start to wear off. At 18k you will see more of the yellow gold content faintly appear. This wear whether 14k or 18k can accelerate depending on the acid of the skin with the person wearing the ring. Every person is slightly different with the PH on their skin. Some people will wear off the rhodium plating faster than others. The other things that accelerate the loss of rhodium is constant washing of the hands with heavy duty soap chemicals and super active activities like gardening and lifting weights. The loss of rhodium will look noticeable in 6-12 months on average. The easy fix is to have a professional jeweler polish the ring and then add another coat of rhodium plating.
When someone wears platinum, the metal does a natural oxidation in time and the metal will start to dull. The appearance will remain white, but not as bright as when it was first ready for wear. The easy fix is to have a professional jewelry polish the ring again with special brushes. The dull effect can happen around 6-12 months of every day wear.
Also, when the rings look brand new the weight of the rings can definitely be noticed if you were to have the same design/dimensions with one being white gold and the other being platinum. The platinum ring is more dense, so it will be heavier. Right now at the time of this article gold is $1300/oz. and Platinum is slightly over $1000/oz. Although gold is higher on the commodity market pricing, the dense metal weight of platinum still makes it cost more for pricing.
Please contact me for further questions. Thank you, Eric