The small erman-speaking enclave around La Calamine in Belgium is known for beautiful samples of contrastfully coloured and nicely banded “Schalenblende” ( crypto- cristallinic Sphalerite), a quite good polishable ore mineral.

However you can find a treat for agate collectors here also (- very rare): petrified wood that has been perforated during the rotting of the trunk by shipworms is found in sedimentary layers. In the course of the process of the silification of the wood substance another result was the formation of agates in these cavities.