Glossary
India (Golconda)
For around two thousand years India was the only known source of diamonds. Stones from the river gravels in the south were traded in the city of Golconda, whose name still stands for diamonds of exceptional purity and transparency.
Famous stones
Some of history’s best-known diamonds come from India, including the Koh-i-Noor and the blue diamond that became known as the Hope. In the 18th century India lost its position to Brazil.
Today
India is now the largest cutting centre for diamonds. As a source it is known for alexandrite from the east of the country; sapphires from the Indian Himalayas are listed under the name Kashmir.
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 2026-10-06