[8] The entire cave lies under a 2 km square area in a layer of Neogene period gypsum that is less than 30 metres (98 ft) thick.

They comprise a dense network on several levels, making Optymistychna known as a "maze cave".

Optymistychna's gypsum bed is topped with a limestone layer, which has seeped through into the cave via erosion and formed into calcite speleothems.

[7] At other places, the gypsum has formed crystals, often tinted a multitude of colors by mineral salts.

In some areas, large gypsum rosettes have formed, colored black by manganese oxide.