A Visit to Coster Diamonds

Royal Coster Diamonds dates back to at least 1840 and is the world’s oldest trusted diamond polishing factory, with a rich and compelling history. Their Diamond Museum is the most extensive museum dedicated to diamonds in Europe. Located at the Museum Square between the Rijks­museum and the Van Gogh Museum, it’s the perfect stop to learn about the magical world of diamonds. I visited Coster Diamonds in January 2020.

A diamond only becomes the diamond we know and admire once it has been cut and polished. Ms. Pauline Willemse, Head of the Polishing Department at Coster Diamonds, has been doing this for more than 30 years.

In the 90s she polished the smallest diamond in the world — with 57 facets, a mere 0.16 to 0.17 mm in diameter and 0.11 mm in height, smaller than the average grain of sand — which earned her a listing in the Guinness Book of Records. Pauline is very charming and friendly, happy to show you how the polishing process works while sharing some exciting stories.

Mr. Herman Thor has worked in the diamond business even longer, for more than 40 years — first at Van Moppes Diamonds, incorporated by Coster in 1995. Herman retired years ago but still enjoys working at Coster for a few days a week. He was kind enough to further explain the polishing process in detail: from rough stone to shiny diamond. He even let me have a go at the polishing machine for a couple of minutes, which was great fun but not an immediate success — diamond cutting and polishing is hard — highly specialized work which takes years of training, practice and patience. Thanks to both Pauline and Herman I had a wonderful afternoon!

Diamonds have always been the subject of many myths and tales. The Romans and Greeks believed diamonds were the tears of the gods, while people in the Middle Ages attributed great healing power to them. The Roman naturalist Pliny said: “Diamond is the most valuable, not only of precious stones, but of all things in this world”.

Coster Diamonds website: https://www.costerdiamonds.com/