Frequently Asked Questions


The USGS studies geologic processes that concentrate mineral resources in the Earth's crust, and assesses areas of undiscovered mineral resources. We also collect national and international information on mineral commodities.

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Image: Hydraulic Gold Mining
The primary methods used to extract minerals from the ground are:  Underground mining Surface (open pit) mining Placer mining  The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use. Higher-grade...
A hole in the ground with layers
The following USGS products will be helpful in determining the background levels of various elements in soils and other surficial materials: Geochemical and Mineralogical Data for Soils of the Conterminous United States (2013) Data for samples collected at three intervals (0-5 cm surficial soils, A-Horizon soils, and C-Horizon soils) across the...
Red fireworks, courtesy of Don-vip,
Mineral elements provide the color in fireworks: Barium produces bright greens Strontium yields deep reds Copper produces blues Sodium yields yellow  Other colors can be made by mixing elements: Strontium and sodium produce brilliant orange Titanium, zirconium, and magnesium alloys make silvery white Copper and strontium make lavender Gold sparks...