It seems that there have been many controversies over opal mining. At the end of the 18th century, the monarch entrusted mining to the Viennese jeweller Joseph Rumpler. However, it was not long before the company Neumány took over the mines tenancy. However, this position did not long in the Slánske vrchy mountains and Josef Rumpler, who had mined opal until 1908, returned to the manage the mines,. This period is also known for the illegal trade in opals, in which Košice traffickers participated.