When buying a loose diamond, what is more important, colour or clarity? This is a very common question asked by purchasers, most often in the form of a trade off (e.g. “Which is better; a diamond with H colour and VS2 clarity, or a diamond with G colour and SI1 clarity?”). However, the question itself contains a false assumption that often leads purchasers to a poor final decision.
Implied in the question, is the mistaken belief that when purchasing a diamond online it is best to set a budget and then decide how to best “use up” that budget on colour and clarity. A better approach would be to consider colour and clarity independent of each other, and decide what the minimum acceptable level is for each attribute. That may lead the purchaser to a diamond under the assumed budget (In the above question, it may be that an H SI1 is a better choice for a particular customer than either an H VS2 or a G SI1).
To illustrate the point, consider if, when purchasing a new car, you have ever asked the salesman “What’s better; a Dolby stereo surround sound and 19 mpg, or a basic radio with 24 mpg?”. Probably not, because the two attributes are not related, and there is no reason to conflate them in an either/or fashion. Instead, you would consider what sound system you desired, and separately what gas mileage you needed. Using these two values, you would then shop for a car that met both minimum requirements.
GIA certified loose diamonds should be purchased the same way. First, a customer would want to consider what colour will satisfy him or her, given the size and shape diamond desired. For most, the minimum colour will increase as the size of the diamond increases, since larger diamonds show more colour. Once the colour question is settled, clarity would be considered. Many customers fall into one of two camps; those that simply want the diamond to have no flaws visible to the naked eye, and those that require a certain degree of flawlessness that goes beyond what they can detect with the unaided eye (such as a VS1 clarity). Once the minimum colour and clarity are settled, those values can be combined with the desired size and cut to determine the approximate price. If the price is outside the purchaser’s budget, it is usually a matter of reducing size (since the colour and clarity are already at the minimum required level).
A common mistake among all diamond buyers is to set too high a minimum on clarity, purchasing a VS2 or better diamond in an effort to make sure there are no visible inclusions, when an SI1 or SI2 would be quite sufficient. Especially in diamonds under 1 ct., SI level flaws are usually very difficult or impossible to see. Another common mistake is to think that by increasing the colour, they will compensate for issues of clarity or cut. This is never true for clarity, and rarely true for cut.
Reference: Lumera Diamonds – please find the original post here.