Diamonds are weighed in metric carats: one carat is equal to 0.2 grams. The carat takes its name from the carob seed.
Because these small seeds had a fairly uniform weight, early gem traders used them as counterweights in their balance scales.

Colorless diamonds are the rarest and therefore the most valuable. The diamond color grading scale consists of 23 graduations,
from the letter D, colorless, to the letter Z, light yellow. In general, the increasing of color in a diamond results in a decrease of its price.

Clarity refers to the state of transparency and purity.
Because diamonds are formed deep within the earth under extreme heat and pressure, they often contain unique birthmarks.
Diamond clarity refers to the absence of these inclusions and blemishes.
Diamonds without these birthmarks are rare, and rarity affects their value.

Cut refers to a diamond’s proportions, symmetry and polish. The beauty of a diamond depends more on cut than on any other factor.
Precise artistry and workmanship are required to fashion a stone so that its proportions, symmetry,
and polish deliver the magnificent return of light only possible in a diamond.