Is 4C System Adequate When We Price Diamonds?

There are seven basic price factors for diamonds: 

♦ Cut quality (Proportions and finish)
♦ Colour
♦ Carat weight
♦ Clarity (Degree to which a stone is free from flaws)
♦ Cutting style & stone shape
♦ Transparency
♦ Treatment status (Untreated or treated? What type of treatment?)

Why the 4C's is Not an Adequate Pricing System? You may be surprised that there are more than four price factors if you've heard about the 4C's of color, cut, clarity and carat weight. The 4C's system of valuing gems is a clever, convenient way to explain gem pricing. The problem is that it causes consumers to overlook the importance of cut quality, treatment status and transparency.

If you see a mini gem-lab report stating that the shape/cut of a diamond is round brilliant, you may assume that this tells you everything about the cut of stone when in fact it doesn't. The quality of the cut is important and it's a separate price factor from shape and cutting style. If you're not informed about gem treatments, you may assume, for example, that two equally attractive diamonds should be priced alike. However, if one is fracture-filled or irradiated and the other is untreated, their prices should be quite different.

If you're comparing a cloudy stone to a transparent one, be aware that transparency can have a significant impact on each stone's value. Transparency and clarity are often interconnected, but they're not the same. A stone can be transparent like crystal, yet have a low clarity. Likewise a gem may be flawless, yet be translucent. More will be discussed in the following sections on transparency.

In short, smart diamond buyers will consider the 5C's and 2T's instead of just the 4C's.