To collect precious stones in Gem Challenge, it is necessary to ensure that the gems of the same species and color are on the game field. At each level, you must first pay attention to the upper right corner. There you will find a sample of stone, which should fill the field. Tiles on the field will be periodically closed and open. In the short moment of opening, find the crystal corresponding to the sample and click on it to fix it. Thus, the field will be filled with the same elements in Gem Challenge.
