The following images of sand from Brighton Beach is 64 times magnified. Individual particles of sand are easily recognizable. Most of the particles have an angular glass like appearance. The particles with no color are made of quartz mineral while the particles with opaque pink color are made of feldspar minerals. The dark colored particles are made of either hornblende or olivine minerals.
The angular nature of the sand particles imply that more than likely they were never transported in riverbed and if they have been transported the river was likely navigable.
The particle size of the sand is medium coarse and the average particle size is about half a millimeters.