During electrostatic bonding of aluminum to Pyrex glass, gamma-Al2O3 is formed on the interface between the two materials in two distinct morphologies. The first, and more obvious, morphology is that of highly textured nanocrystalline structures growing from the interface into the glass. These nanostructures have a distinct effect on the width of the sodium-depletion layer formed in the glass and are associated with precipitates in the aluminum adjacent to the aluminum/Pyrex interface. The second morphology of gamma-Al2O3 is an anodic oxide layer on the interface between the two materials. Together, these two morphologies enable strong bonds to be made.