Diamond Quality Parameters

Diamond Quality Evaluation

Before one can truly be confident in selecting and purchasing diamonds he or she should have knowledge about important diamond features, significant propertires and parameters that determine a diamond's quality, as it is presented in international diamond standards.

Professional jewelers use magnifying equipment in order to detect a diamond's flaws. Diamonds that are certified by reliable institutes have already passed a series of tests, resulting in a thorough description of their characteristics as well as rating of their most important attributes. A diamond consumer can generally trust such a certificate, but problems arise when no such document is available or when one cannot be certain whether the certificate provided by a dealer actually matches the diamond in focus. It's recommended to be aware of the four C's (carat, clarity, color and cut), which are parameters which have a big influence on a diamond's price, and to understand the meaning of each on of the them.

The Four C's

Carat is the weight unit used to measure a diamond. 1 carat is equal to 0.2 grams. A carat is consisted of 100 points, therefore a 50 points diamond could also be regarded as a half carat stone. Each additional point increases the price of a diamond significantly. Although carat is a weight unit, many also refer to the carat number as the size of a diamond, because there is significant correlation between weight and size of diamonds. Therefore, if a diamond expert knows the shape and weight of a diamond he or she could also know its approximate size.

Clarity is a property that refers to how many and what size if inclusion a diamond incorporates, in other words how clear it is. Besides the obvious aesthetic value, the clarity level also has effect on the manner light is reflected by a diamond. The international clarity grading standards rate clear diamonds as Flawless (F), while diamonds with visible inclusions are graded by the letter I. In the middle of the scale are the additional SI, VS, VVS and IF grades (from less clear to clearer).

A grade of a diamond's color usually refers to white diamonds. Colorful diamonds such as red, pink, black and yellow are very rare, thus are not graded by the common rating. The more colorless a 'white' diamond is the highest rating it receives. 'D' represents a colorless diamond, while 'Z' represents a yellowish stone, the lowest color grade. As the letter grade proceeds along the alphabet from D to Z to less colorless the diamond is.

Along with carat weight, cut may be the most important feature of a diamond. The cut and polish results in a diamond's shape (such as round, emerald, pear, etc), but also within identical shaped there are minor, yet meaningful, differences in the cut of stones. The more symmetric a diamond is, the more its facets are well proportioned, thus the higher cut grade a diamond has. A cut of a diamond has a prominent effect on it's brilliance, thus and ideal cut stone projects a remarkable spark. A long with 'ideal', other cut grades are 'very good', 'good', 'fair' and 'poor'.

When it comes to selecting a natural diamond, the four C's are very important factors. It is also recommended to ask the jeweler if a desired diamond has been treated in any method, such as laser drilling, painting, insertion of glass fillers, etc. Such treatments may have misleading effect on an evaluation of a diamond, as well as make it more fragile and shorten its lifetime.

Evaluating a price of a diamond, based on its specific four C's parameters can be done through the following Rapaport Diamond Price Calculator:   http://www.diamondsnews.com/rapaport_diamond_prices.htm#price