Skip to main content
U.S. flag

An official website of the United States government

Spectral Library

Researchers at the USGS Spectroscopy Laboratory have measured the spectral reflectance of thousands of materials in the lab and compiled them in the USGS Spectral Library.

The spectral library was assembled to facilitate laboratory and field spectroscopy and remote sensing for identifying and mapping minerals, vegetation, and manmade materials.For many of the samples, wavelength coverage spans the ultraviolet, visible, near-infrared, mid-infrared, and far-infrared regions (0.2 to 200 microns).A wide range of materials are included in the library:MineralsSoils (including rocks, and mineral mixtures)Coatings on rock surfacesLiquids, including mixtures of liquids, water and other volatiles, and frozen volatilesOrganic compounds, including biochemical constituents of plants and chemical compoundsManmade materials, including materials introduced into the environment by human activityVegetation and other biologic materialsDetailed sample descriptions are provided with the spectra, including the results of X-ray Diffraction, Electron Probe Micro-Analysis, and other analytical methods.