Ferric Iron Index

Geological index for detecting ferric iron (Fe3+) concentrations in rocks and soils. Useful for lithologic mapping and identifying iron-rich mineral formations. Geological indices identify mineral compositions and lithological features by targeting diagnostic absorption features in shortwave infrared wavelengths. Different minerals produce unique spectral signatures that these indices isolate. Fe3+ is particularly suited for geology, mining, heavy metal detection. The general formula is Red / Green, which requires Green and Red spectral bands.

Fe3+ is supported by 23 satellite sensors in our database, including BJ3A, BJ3N, Dragonette-1, Dragonette-2/3, Gaofen-1 and 18 more. Each sensor uses different band designations — for example, BJ3A uses the formula Red / Green, while BJ3N uses Red / Green. Select a sensor above to see its specific band mapping.

Fe3+ requires Green (520-600 nm), Red (630-690 nm). These specific wavelength regions correspond to diagnostic mineral absorption features caused by electronic transitions and vibrational overtones in crystal lattices.

Both Python and R code samples are provided above. In Python, use rasterio to load individual band GeoTIFF files and numpy for the arithmetic. In R, the terra package handles raster operations efficiently. The key is to load bands as floating-point arrays to avoid integer division, and to handle division-by-zero cases where the denominator equals zero. For production use, consider applying a valid data mask to exclude no-data pixels before calculation.

Geological index for detecting ferric iron (Fe3+) concentrations in rocks and soils. Useful for lithologic mapping and identifying iron-rich mineral formations. For accurate mineral identification, this index should be used alongside other geological indices and validated with field samples or known geology maps. Spectral unmixing or supervised classification using multiple indices typically yields more reliable results than any single index alone.