Quality Characteristics of Black Diamonds

Black diamonds are valued very differently from classic colourless diamonds. While the 4Cs (carat, colour, clarity, cut) are crucial for the latter, other criteria apply to black diamonds. Due to their intense colour resulting from numerous inclusions, clarity plays a secondary role. Instead, the following aspects take precedence:

Colour: 

Colour is the key quality characteristic of black diamonds. A deep, uniform black is considered ideal. Natural black diamonds get their colour from inclusions of graphite or iron oxide, while treated stones are blackened by irradiation. The deeper and richer the black, the higher the value.

Cut:

Cut is also very important for black diamonds. An excellent cut enhances the brilliance and light reflection despite the dark colour. Because black diamonds are often more porous and brittle, cutting them requires special skill to bring out their full aesthetic appeal.

Carat Weight:

The weight in carats is another factor that affects value. Larger black diamonds are rarer and therefore more desirable. However, compared to colourless diamonds, weight has less of an impact on price because colour and cut dominate the visual appearance.

Surface Quality:

As clarity is of little importance for black diamonds, the focus is on surface quality. Attention is paid to cracks, scratches or other imperfections that could affect the appearance or durability of the stone.