The gemstone laboratories | Unsaid Library

The gemstone laboratories Gemstone laboratories are exclusively concerned with the evaluation of polished gemstones. The four “C’s” described above are assessed using the most modern means and techniques. The end result is laid down in the certificate on which the details of the four assessments are stated with as extra assessment the “Finish Grade”, which…

How do they determine the colour and quality of a diamond? | Unsaid Library

Judging the colour of the diamond How a colour diamond is judged is rather subjective. A pure diamond is colourless. Usually, the less color, the purer, so the more valuable it is. Certain relatively common discolourations, such as yellow, reduce the value of the diamond. Of course these stones remain valuable; in 2011 a yellow…