The Romans, like the Egyptians and much more than the Greeks, used polychrome stones for decorative purposes in architectural elements, floor and wall facings and statuary. Throughout their Mediterranean provinces they systematically searched for and exploited a very large number of beautiful lithotypes, many of which they distributed to all corners of their empire. The most important of these stones were often re-used later in medieval-to-modern times; some of them are still offered on the market. They include granitoid rocks (granites, granodiorites/tonalities, gabbros, quartz-monzonites), a few lavas, many metamorphites (impure marbles, metabreccias and metandesites) and several sedimentary rocks (limestones, lumachellas, conglomerates, calcareous alabasters/travertines). The 40 most important and widespread of these lithotypes are considered here as regards their origin, the history of their use and their minero-petrographic characteristics, which can contribute to better knowledge of single species, to determination of the original quarries and to archaeometric solutions of several provenance problems.