Cut refers not to a diamond’s shape (e.g. round, oval, pear, etc.) but to a diamond’s proportions, symmetry and polish. The beauty of a diamond depends more on cut than any other factor. Though extremely difficult to analyze and quantify, diamond cut has three primary effects on appearance: brilliance (the brightness created by the combination of all the white light reflections from the surface and the inside of a polished diamond), fire (the dispersion of light into the colors of the visible spectrum, seen as flashes of color), and scintillation (the flashes of light and dark, or sparkle, when a diamond or light source is moved).
Clarity grading determines the relative visibility of the inclusions in a diamond and their impact on the overall visual appearance. The importance of clarity in diamond value originates from the notion that as diamond clarity improves, diamonds increase in rarity.
A stone plot on a diamond grading report is a bit like a fingerprint. It records the significant internal and external characteristics of the diamond as a way to help positively identify that diamond and justify its clarity grade.
The diamond color evaluation of most gem-quality diamonds is based on the absence of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value.
Diamond carat weight is the measurement of how much a diamond weighs. A metric “carat” is defined as 200 milligrams.
Each carat can be subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its ‘points’ alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a ‘twenty-five pointer.’ Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as ‘one point oh eight carats.’
Leakage is harder to see if light is blocked from entering the back of a stone.
The more enclosed the setting the less back light. Aim for good even light from behind the stone, but beware of direct glare; it will make facets look pale and shiny.
Fancy cut Diamonds :
As a diamond consumer, you’ve probably heard the term “diamond treatment” or “treated diamond,” or perhaps “enhanced diamond” and wondered what that meant. A relatively small percentage of gem-quality diamonds are treated and they are treated for two reasons: to improve clarity or to alter color.
Synthetic diamonds grown in a lab are virtually identical to natural diamonds, but that’s where the similarities end. In fact, there are two distinctive methods used to grow synthetic diamonds.