pavonazzo

Rather, the worn organic colors of the ancient earth and stone of which the city is composed, the colors of limestone, the ruddy gray of tufa, the warm discoloration of once-white marble and the speckled, rich surface of the marble known as pavonazzo, dappled with white spots and inclusions like the fat in a slice of mortadella.

The Forever City Robert Hughes 2011

In order to make his flesh colouring easier to paint Buonamico used a ground of _pavonazzo di sale_, as is seen in this work, which in the course of time has caused a saltness by which the white and other colours are corroded and consumed so that it is no marvel that the work is damaged and destroyed, while many that were made long before have been excellently preserved.

The Lives of the Painters, Sculptors & Architects, Volume 1 (of 8) Giorgio Vasari 1542