About Royal Coster Diamonds
In 1840, Moses Elias Coster founded a diamond polishing company in Amsterdam that is now the oldest in the world. In 1852, we repolished the famous Koh-i-Noor diamond for Queen Victoria, and in 2016, we were awarded the prestigious Royal designation.
To this day, our skilled craftsmen polish diamonds themselves, while our goldsmiths create exquisite jewelry in house. With over 20,000 loose diamonds, we hold one of the largest diamond collections in Europe.








