A carat (ct.) is the unit of measurement specifically used to describe the weight of a diamond (or other gemstones). Its name comes from the carob seed – a small seed with a typically uniform weight that early gem traders used as counterweights for balancing their scales.
Diamonds occur in a variety of colours — steel gray, white, blue, yellow, orange, red, green, pink to purple, brown, and black. Coloured diamonds contain interstitial impurities or structural defects that cause the colouration, whilst pure diamonds are perfectly transparent and colourless.
Diamond clarity is a quality of diamonds relating to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects called blemishes. Inclusions may be crystals of a foreign material or another diamond crystal, or structural imperfections such as tiny cracks that can appear whitish or cloudy. The number, size, colour, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under ten time’s magnification.
Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond's cut as shape (round, emerald, pear), but a diamond's cut grade is really about how well a diamond's facets interact with light. Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry, and polish deliver the magnificent return of light only possible in a diamond.