  The recent synthesis and characterization of bilayers of vitreous silica has
produced valuable new information on ring sizes and distributions. In this
paper, we compare the ring statistics of experimental samples with computer
generated samples. The average ring size is fixed at six by topology, but the
width, skewness and other moments of the distribution of ring edges are
characteristics of particular samples. We examine the Aboav-Weaire law that
quantifies the propensity of smaller rings to be adjacent to larger rings, and
find similar results for available experimental samples which however differ
somewhat from computer-generated bilayers currently. We introduce a new law for
the areas of rings of various sizes.
