Although numerous hypothetical growth processes have been studied by computer simulation, only a few appear to describe any objects in nature. This paper presents a new model of random growth, whose rules are based on the local chemistry of the hydrolysis and polymerization of tetraethoxysilane, Si(OC₂H₅)₄, and which mimics some of the different random structures that can form under different chemical conditions. The fractal geometry of polymers derived from alkoxysilanes is examined. -- AATA