Maxima Studio –Texture collection 'Grounds' wich has nine themes:
Earth, Flowers, Grass, Leafs, Asphalt, Cement. Sand, Stones, Tiles .
“Sands” theme have 17 files with bump map in resolution 1024x768 pixels.
All the pictures are JPEG compressed at high quality in 24 bits (16 milion colors).
The provided opacity map is ideal for making multi-layered materials.