Ruin marble
Ruin marble is a kind of limestone or marble that contains light and dark patterns. It originates mostly from the city of Florence in the commune of Tuscany, in Central Italy. Its color pattern consists mainly of gray, brown and reddish, sometimes also blue and black, giving it the impression of a ruined landscape painting. The patterns (similar to Liesegang rings) develop during diagenesis due to periodic rhythmic precipitation of iron and manganese hydroxides from oxidizing aqueous fluids restricted laterally by calcite and clay filled joints.