After its discovery, the Trojarova deposit was explored in the first phase by drillholes and in the second phase by the Trojarova adit. The drillholes intercepted a high quality Sb mineralization, which was to be opened by the adit. The adit started to be excavated in the 1990s from the state budget until a German investor from Koln entered the project. However, the investor did not fulfil his financial obligations at an advanced stage of the underground exploration and the project was stopped. Therefore, the adit did not reach the part of the deposit with rich ore.

The ore resource with Sb content above 2% in the adit is very small (only 2 channel samples had Sb content above 2%). This means that no “economically recoverable” ore is available in the Trojarova adit. The adit would have to be extended by several hundred metres to make the rich ore available.