Consolidants are materials that are applied to damaged stone to restore its strength. A variety of polymers and ethyl silicate compounds have been in use for decades, but each of them has its disadvantages. We are interested in providing a broader range of properties by incorporating colloidal oxides into an ethyl silicate solution. The example above compares the performance of stones subjected to a salt crystallization test. Our particle-modified consolidant (PMC) shows much better resistance to damage - but the particles (titania, in this case) - whiten the stone too much. We are exploring a variety of other oxides to optimize the performance and color. We hope to produce a palette of consolidants that will be suitable for any stone. Our progress to date is described in several papers.