Why do diamonds of the same color and clarity grade have different prices?

Have you ever wondered why diamonds with the same color and clarity grades have different prices? The main factor behind these price differences is the diamond's cut.

Diamonds can be cut into various shapes, which affect their proportions, symmetry, and light dispersion. A high-quality diamond must have optimal proportions—ideally 3 Excellent or at least Very Good grades. When light enters a diamond, it should reflect back out from the top. If a diamond is cut too shallow, light will leak out of the bottom, while if it is cut too deep, light will leak out of the sides.

A good cut enhances a diamond's sparkle when exposed to light, as the ideal light performance ensures that all light is reflected back toward the wearer, providing maximum brilliance.

Many people may have heard the term "Belgian diamond" when shopping for diamonds but aren't sure what a "Belgian cut" is or how it differs from others. It is worth noting that Belgium has been a renowned hub for highly skilled diamond cutters since the past, maintaining its prestige to this day, and is very popular in Thailand. A Belgian cut refers to a diamond polished using the latest modern high-tech digital technology, which has made Belgian-cut diamonds a favorite among those in the diamond industry.

These different facets result in varying levels of diamond sparkle. This difference alone can cause cost variations of up to 20% between shops, which is the reason why diamonds of the same color and clarity do not always have the same price.