Some unusual gemstones in the collection of the Rijksmuseum van Geologie en Mineralogie of Leiden

Our Museum can take pride in a very valuable gem collection for, besides the numerous specimens which were gathered by King William I of the Netherlands a great many of the more unusual stones are to be found in it. Especially since World War II the Museum has acquired many interesting and important stones by gifts and purchases. This enlargement is especially due to the efforts of Professor Dr. B. G. Escher, who was continually aimed at the acquisition of rare and unusual stones for the gem collection, bringing it gradually up to modern standards. As in so many gem collections, one finds stones which are not suitable for wearing, because they are soft or easily cleavable. It is surprising to see the variety of minerals that have been cut in recent years and which are scarcely suitable as gems for this reason. They are collectors’ stones only.