Glossary
Secondary hue
A secondary hue is a second colour visible alongside the dominant one. Laboratories write it as an adjective before the main colour: «purplish pink», «orangy yellow», «bluish green». «Slightly» indicates a small share. Coloured diamonds may carry two secondary hues, for example «Fancy Deep Brownish Orangy Yellow». The dominant colour always comes last.
Read more
- KnowledgeHow to read a gemstone dossierA dossier brings together everything that describes a stone – from the laboratory report to custody. Here is how to read it in the right order.Read more
- Laboratory reportsUnderstanding a laboratory reportA laboratory report is a gemstone's most important document. Which information it contains, how to read it and what it does not say.Read more
- GlossaryAbsorption spectrumWhen light passes through a gemstone, the stone absorbs certain wavelengths – the rest make up its colour.Read more
- GlossaryAfghanistanAfghanistan is an old source of ruby and emerald; both are mined in the mountains of the Hindu Kush.Read more
Updated 2026-10-04
