Ores from hot water
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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.
Topic: Earth Science
Subtopic: Minerals and Resources
Keywords: Hydrogeology, Magmas, Metals, Natural resources
This boulder of nearly pure quartz formed when hot silica-bearing waters flowing through a fracture deposited quartz.
Water leached the metal molybdenum out of hot granite and deposited it in cooler granite, in veins that can be seen to crisscross the rock.
The veins in this rock contain white calcite, milky quartz, and microscopic silver, cobalt, and arsenic-rich minerals, which make up the metallic part of the veins.