The larger a diamond, the rarer it is. The weight of a diamond is measured in carats. 1 carat corresponds to 0.2 grams and is divided into 100 points.
All natural diamonds contain various internal characteristics. Many of these features are invisible to the naked eye. Therefore, a special 10-fold magnifying glass serves as a basis for their recognition. The so-called inclusions determine the clarity classification depending on their number, colour, type, size as well as position. Large inclusions reduce the brilliance. The purer the diamond, the rarer its occurrence.
Most diamonds are colourless to slightly yellowish or brownish. These nuances are divided into colour categories. Basically, the finer the white, the rarer the diamond. Extremely rare are the natural diamonds in the colours red, pink, blue, green and intense yellow.
The proportions are decisive for the brilliance and fire of a diamond. The symmetry evaluates the possible deviations in the facet arrangement. The polish describes the condition of the facet surface.