A vocabulary of landscape — a landscape of words
1083 entries
breccia
Rock made of angular broken fragments cemented back together in a finer matrix. The angularity is the point: It means the pieces were buried close to where they broke, without the tumbling that would have rounded them. Conglomerate is the same idea with rounded clasts and therefore a longer journey. Breccia forms at fault zones, in collapsed cave systems, on scree slopes, in volcanic vents, and under meteorite impacts.
Etymology
Italian breccia, gravel or rubble, taken into English in the 1610s along with a good deal of other quarrymen’s and stonecutters’ vocabulary from Italy. The Italian is thought to be Germanic in origin, from a root meaning to break, so it is a distant relative of English break and breach. A word for broken stone that is itself a broken-off piece of another language.
Notes
Impact breccias are how a crater is confirmed long after the crater itself has eroded away — the shattered rock survives underground with shock features in the quartz that nothing else produces. Many prized ornamental marbles are breccias, which is why the polished slab in a bank lobby often looks like a smashed plate reassembled.