When many people think of a diamond cut, they are typically thinking of the shape (round, pear, marquise, etc.) instead. However, the cut refers to the quality and amount of light that passes through a diamond.
When a diamond is cut properly at the highest quality or an "ideal cut," the greatest possible amount of light reflection will occur in the diamond, creating their famous sparkle. The lowest quality cut diamond, or "poor cut," refers to a severely shallow or deeply cut diamond.
If a diamond is cut too deeply or shallowly, it can reduce the shine and, consequently, reduce the value. If a diamond is cut too shallowly, it will allow light to pass straight through and create a more dull looking diamond. Likewise, if the diamond is cut too deeply, light will hit the diamond in a way that it will be reflected from the side on the bottom, also reducing the amount of sparkle that is desired.
When looking at a piece of authentic jewelry, it should have a stamp in a discreet spot that tells you what the content of the metal is.
For example, usually, on the inside of a gold ring, it will be stamped with
- 10K (10 out of 24 parts)
- 14K (14 out of 24 parts)
- 18K (18 out of 24 parts)
- 22K (22 out of 24 parts)
- or the purest form of gold, 24K (24 out of 24 parts), however, 24K gold is too soft for jewelry use.
By doing the division of each number over 24, this will tell you the exact percentage of gold in the piece of jewelry.
In silver, you will often see a three digit number such as .925 sterling or 925 sterling; this means that the metal is 92.5% sterling silver.
For platinum, you will also see a three digit number such as 900 which means that it is 900 out of 1,000 parts or 90% platinum. Platinum may also be abbreviated on the inside of the ring or another discrete spot on the piece.
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.