The carat of a diamond is determined by the weight of the diamond. The bigger the diamond, the higher the carat weight. One carat is equal to 200 milligrams. The carat of a diamond will determine the value and price of the gemstone.

The price of a diamond rises exponentially as the carat weight increases. The value of a diamond of 2.00 carat is more likely triple the price (and not double) of a 1.00 carat diamond with similar characteristics.

Especially the symbolic value of carat for diamonds cannot be overstated. For example, the difference between a 0.98 ct. diamond and one of 1.01 ct. can hardly be seen, but their prices might be much further apart than you would expect. The difference in price can be explained by the fact that we cross a ‘magic size’. Magic sizes are, for example, 1 carat, 1.50 carat or 2 carats. Once we reach that magic size, the price increases exponentially.

An international colour gradation system provides a code from D to Z, where D is fully colourless and Z is a yellow hue. A diamond with colour D is the most valuable. The colour of colourless investment diamonds varies between D and G.

There are also coloured diamonds, in brown, orange, pink, red, yellow, green or blue. Depending on their colour, some are incredibly rare, which also determines their monetary value. In general, their price is higher than the colourless diamonds due to their rarity. Very intense coloured diamonds are called fancy coloured diamonds, and this is always listed on the certificate.

We have noticed that there is only a very small market for especially rare diamonds (very large, coloured and with a fancy cut). Would you like to invest in coloured diamonds? The experts at BNT Diamonds are happy to assist you.

The vast majority of all diamonds have inclusions – impurities on the inside of the diamond. Most inclusions are not visible to the naked eye. The diamond is given a score after experts from an institute like GIA have studied it for impurities under a tenfold magnification through a microscope.

Inclusions can obstruct the sparkle of a diamond. They block the reflection of light if they are in the path of the light.

Of course, impurities should not impeach the beauty of the diamond. To guarantee that, we only select diamonds with inclusions that are not visible to the naked eye.