When quartz grains are poured into a glass, they will accumulate at the bottom of the glass in an arrangement matched to their sizes.
It is common for the grains of larger diameter to be deposited at the bottom of the glass, while those of smaller size are being deposited further up. This deposition is not done in an organized way, since the quartz grains were dumped in no organizational order.
The figure below shows a possible way of how these grains would be organized in the cup.
