Mineral assemblages surrounding ore deposits typically have unique characteristics that create zoning patterns (changes in composition with depth, lateral distance, or both) in a variety of ore deposit environments. These patterns result from the interaction of hydrothermal fluids with the surrounding host rock and may be used to help locate mineralization. Mapping alteration minerals—that is, determining the type and distribution of alteration minerals in a given area—is therefore extremely useful in identifying and outlining mineral deposits. It is a routine part of exploration for hydrothermal mineral deposits and aids in the assessment of exploration properties and the construction of deposit models. Short-wave infrared (SWIR) spectroscopy is used to identify these alteration minerals and focus exploration programs.