GRAIN: Geotechnical Repository of Annotated Individual-Particle Images V1.0

The database contains particle-level images and associated size and shape descriptors for six geotechnically significant sands: Ottawa 12–20, Vieques, Cape Cod, Fiji Pink, Peace River, and Hawaii. Individual particle images were acquired using a QICPIC Dynamic Image Analysis (DIA) system at a resolution of 4 µm/pixel and are provided as isolated binary particle silhouettes in PNG format. The accompanying metadata contain particle-level size descriptors, including minimum and maximum Feret diameters and equivalent projected-circle diameter, as well as shape descriptors including aspect ratio, sphericity, convexity, and roundness.