It was worth the risk of the darkness and the distance.

Archaeology can say with reasonable probability: the minerals served purposes that combined practical utility with ceremonial significance, because that is the pattern that human cultures typically display when they invest sustained effort in obtaining specific materials from difficult-to-access environments.

Archaeology can say with appropriate uncertainty: the specific purposes included some combination of pigment use, medicinal application, trade value, ceremonial application, and possibly agricultural or food preservation function, with the balance among these purposes changing over the long mining period.

What archaeology cannot say: exactly what the darkness meant to the people who went into it, exactly what the minerals meant in the specific ceremonial or cosmological frameworks of the communities that used them, exactly what knowledge was transmitted from one generation of miners to the next, and exactly what was lost when the mining stopped and the cave was left.