Diamond color is graded on an alphabetical scale from D-Z, D being colorless, and Z being the most yellow/brown. The closer the diamond color is to D, the higher the price will be, considering that D is the rarest color to achieve from any diamond.
The diamond color scale is split up into four different sections to categorize and seclude diamonds of similar colors from those of different colors.
The first, most expensive, and highest quality colors are first on the scale, D-F; these colors are virtually colorless and the most desirable in a diamond.
G-J, which are nearly colorless.
K-M which are slightly yellow
N-Z are the diamonds that are light yellow or brown.
Many jewelers will not even carry diamonds of the colors N-Z due to how low their quality is and how much it reduces the value of the diamond.
When buying jewelry, especially gold, the higher the karat, the heavier the metal is. A 10K ring would weigh less than a 14K ring of the same size. The heavier the metal, the more it tends to cost due to the amount of precious metal in the jewelry piece. Platinum is heavier and also more expensive than a piece of gold.