Ticket reservations are required. Facial coverings are strongly recommended. See Health and Safety.
Part of Hall of Planet Earth.
In some large bodies of magma, or molten rock, the minerals that crystallize settle to accumulate on the chamber floors, which slowly build up until the magma is completely solidified. The minerals accumulate in layers, depending on when they formed in the magma. This is one natural sorting process that may concentrate valuable metal-rich minerals.