In Yellow or White, get Gold diamond rings !!

Gold diamond rings are the most common of the diamond rings....common in comparison to Platinum though. Gold diamond wedding rings are the most common as you can get away with having accent diamonds on the ring which are cheaper than having a large center diamond as commonly found in engagement rings.
However, you won't find everyone sporting one even though gold has been around and valued since prehistoric times.
It may have been the first metal used by human beings for rituals and making jewelry.

Gold is the most malleable metal know meaning it can be very easily shaped & also very ductile meaning it can be stretched without breaking.
One gram of gold can be beaten in to a square sheet 1 meter sq.
It can also be beaten so thin it becomes translucent.
Pure 24 Carat gold is very soft and since it easily forms alloys, it is mixed with other metals which increases the hardness or creates unique colors.

This is important when making gold diamond rings due to wear and tear of every day use.
If left as 24K, the rings would bend and maybe any Diamonds on the ring would fall of as the gold stretches.
White gold is a very popular alloy of Normal gold....which by the way is Yellow in color.
Nickel is toxic and reacts with some people but there are Palladium alloys of gold available which are also white in color but more expensive than the Nickel ones.

The higher the Gold K the more pure the gold; 22k 18k 14k and 10k gold contains more of the Copper or Silver base metals in the alloy.

Due to the malleability of gold and its unique contrast to Diamond, combining the two was a natural progression & so gold diamond rings were born.