The 4 C’s Of Diamonds


The term cut refers to the facets, and their proportions, on the surface of a diamond. We operate within stringently applied guidelines and explicitly defined relationships between the table, the crown, the pavilion and the girdle of every stone. Carat weight is wrongly thought by many to be the most important factor in deciding the value of a diamond. Unfortunately, this misconception has led some diamond cutters to take advantage of the first-time buyer. For example, some diamond cutters will leave an excessively thick girdle around the stone, increasing the diamond’s carat weight. This practice harms the stone, considerably impairing the diamond’s beauty and brilliance. We continuously go to immeasurable lengths to provide you with diamonds having precise, intricate angles that generate incomparable beauty.


A diamond’s clarity rating is the key measure of its overall quality. Nature guarantees that almost all diamonds have inherent natural blemishes called “inclusions.” Often, these clarity shortcomings are invisible to the untrained eye. However, these same imperfections are immediately apparent to a professional gemologists. We operate with the highest standards in the industry, continuously and unequivocally rejecting diamonds that do not meet our criteria. A stone is said to be flawless if, under magnification, no inclusions like “clouds,” “pinpoints,” or internal crystals; no internal flaws, sometimes referred to as “feathers;” and no external imperfections, such as scratches, burns or abrasions, are visible.


CLOUDING: Milky clouding can produce a dull stone. The degree of penetration into the diamond affects the overall purity of the stone.

SUBSTANTIAL CRYSTALLIZATION: All natural diamonds, even the best, have a slight internal crystallization: a mark that occurs as the crystal forms. However, substantial crystallization constitutes a considerable flaw on the surface and sometimes in the depth of the diamond. It is manifested by veins, waves or minuscule cracks.

NODES: It is not unusual to see a diamond crystal, or node, within the diamond, which reaches up to the surface of the stone. While accepted by some jewelers, we at Robinson’s do not sell diamonds with this type of flaw.

NATURALS: Some gem cutters leave a part of the original surface of the crystal in its rough state when cutting the facets of a diamond. These parts are called “naturals,” and they can change the appearance of the diamond. While accepted by some jewelers, we at Robinson’s do not sell diamonds with this type of flaw.


In nature, the absence of any color is very rate as most diamonds contain tiny amounts of nitrogen. The untrained eye may not be able to detect these minute variations of color, but these distinctions affect the rarity and ultimately the value of your diamond. The color of every diamond is skillfully determined by a certified gemologist. Our’s are typically graded by the most respected gemologists in the industry from either GIA. Color is rated according to a precise scale, running from “D” (colorless) to “Z” (saturated). If a stone has a borderline color classification, we assign it the lower rating. Past “Z” a diamond’s color is considered “fancy.” Fancy colored diamonds are very valuable and, correspondingly, are graded by very different parameters. We subject all the diamonds to a customary color examination according to make sure it adheres to our personal standards of what we sell, regardless of any previous evaluations.


A carat is equivalent to .2 grams and is the unit of weight for diamonds. The value of a diamond increases in an exponential manner. Consequently, in the rare cases when two stones are of the same quality, the larger will have the greater value. For example, a two-carat diamond is not double the price of a one-carat diamond of the same quality, but rather will be worth more than two times a one-carat diamond of the same quality. Larger diamonds of high quality are extremely rare and are valued to reflect that rarity.

(note: charts not scaled to actual size)