COLOR is rated on a scale from D-Z. D-grade diamonds has absolutely no nitrogen, and the lower you move down the scale towards Z, the more nitrogen is present which brings along a warmer color of yellow and brown body tone. No color grade is BAD; it all depends on personal taste and metal colors {white, yellow gold, or plat.}
CLARITY refers to a diamond “inclusions,” meaning included crystals such as garnet, peridot; fractures or scratches from other diamonds. The clarity scale ranges from F-flawless to I-included. Flaws decrease the value of the gem, most are invisible to the naked eye. It makes all the sense in the world to buy one with inclusions unless you have a great deal of disposable income.
CARAT refers to a diamond’s weight not its size. Generally the larger the crystal the more it will cost. The shap will also yield a different price