In the sixties, the large coal dump of the former mines ignited, forming fumaroles that produce interesting cristals…The old dumps are huge, and it is quite a climb upto the mountain (that is in Dutch relative hight…). Collecting is only worth while after a week without rain as many specimen dissolve.

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

•