- Cut, which affects a diamond's brilliance, as brilliance relies on light optics and the ideal angles to produce the maximum effect. A deeply cut stone will affect the way light reflects in the mass of the diamond. A very shallow cut stone will seem dark because the light exits the back of the stone and the angles do not reflect the light back up through the top of the stone to your eye.
- Clarity, which is determined by the amount and severity of inclusions and flaws visible under 10-power magnification
- Color, the less color a diamond shows (i.e., the whiter it appears), the better diamond it is. The exception includes extremely valuable "fancy colored diamonds" and less expensive enhanced "irradiated" stones
- Carat, which is the traditional measuring unit of a diamond's weight (1 carat = 200 milligrams). A carat is divided into 100 "points," so the same diamond can be represented as weighing a carat and a half, 150 points or 1.50 carats.
Moissanite jewels are inspected by trained graders and are scored on a scale specific to moissanite. All of the jewels sold are of "very good" quality, so unlike some other jewels, you will not find moissanite that is off-color or visibly imperfect. All of the jewels sold are of good color and are "eye clean," meaning you cannot see imperfections with the naked eye. Because its physical properties are different than a diamond, moissanite is not graded in the same manner. Cut and carat weight are fairly similar, but moissanite weighs differently than diamond, so it is not an "apples-to-apples" comparison. The retail cost of moissanite is based upon the cost of the gold and the setting in addition to the cost of the jewel. As a general rule, with all other things being equal, a moissanite retails for about 1/10th the cost of a diamond.
Moissanite gemstones are such a close match to diamonds that even skilled jewelers cannot tell the two apart. Like diamonds, moissanite gemstones have inclusions and color differences. Charles & Colvard's patented Tester Model 590 (photo below) is the only recommended instrument that has been developed to distinguish moissanite from diamonds. The tool reliably and easily distinguishes colorless moissanite gemstones.