Ores from hot water

Part of Hall of Planet Earth.

Ores from Hot Water AMNH/R.Mickens

Driven by heat from bodies of molten rock in the crust, hot water circulates through cracks, dissolving minerals in the rocks through which it passes. As the water moves into cooler rocks, the dissolved minerals precipitate and accumulate in fractures and cavities. Many metallic ore deposits, such as those represented in the samples shown here, form in this way.

Ore Formation_ILL

In This Section

Exhibit Giant quartz vein This boulder of nearly pure quartz formed when hot silica-bearing waters flowing through a fracture deposited quartz. Exhibit Ores in granite Water leached the metal molybdenum out of hot granite and deposited it in cooler granite.  Exhibit Silver-rich veins The veins in this rock contain white calcite, milky quartz, and microscopic silver, cobalt, and arsenic-rich minerals.