Typical pattern of stratification of granular mixtures. The white grains are
spherical glass beads of diameter 0.27 mm, while the red grains are sugar
crystals of cubic shape and average size 0.8 mm. We poured an equal-volume
mixture near the left edge between two transparent vertical plates separated
by a gap
of 5 mm. We obtained stratification with a wavelength of 1.2 cm.
Close-up photograph of the stratification pattern above, field of view 40mm
Stratification obtained using a mixture of three different types of grains:
nearly spherical glass beads (0.15 mm, angle of repose 26), blue sand (0.4 mm, angle of respose 35), and red sugar crystals (0.8mm, angle of repose 39). We
notice the grading (from bottom to top) in a triplet of layers:
small (white), medium (blue), and large (red) grains.
Close-up photograph of the 3 grains experiment.