ICE, ICE BABY...
Diamonds should be a major offered in college. Their grading is complex, even for the seasoned jeweler. The subtle differences of many diamonds aren't recognizable to the naked eye. But if you plan to drop G's on a diamond or other precious gem ring, start by learning the four C's.
Carats are a weight measurement based on grams. The higher the carat count, the more expensive the diamond. The average engagement diamond is about half a carat (.50) Some engagement rings have 20 carat diamonds or more.
Clarity refers to how clear a diamond is. Virtually all diamonds have small marks or inclusions, but the more transparent and flawless, the more expensive. The GIA clarity scale ranges from Included (I) to Flawless (FL.)
Similar to clarity, the ideal diamond color is perfectly clear, without any tinge. The GIA color scale ranges from Near Colorless (Z) to Colorless (D.) Deeply colored diamonds are, ironically, quite valuable and not rated on this scale.
Different than SHAPE, a raw diamond is cut and faceted using tiny, precise angles and quality execution. A perfectly cut diamond will sparkle and reflect lots of colored light. The GIA cut scale ranges from POOR to EXCELLENT.