Chios Portasanta Marble Quarries

Marmor Chium

QuarryAsia · near Chios town, Chios, GreeceBuilt 100 BCE

About

Quarries near the island's main town produced a mottled red-and-white marble that Romans called marmor chium, among the most expensive stones in the ancient trade. Greek quarrymen had worked the site before Rome, but Roman demand from the 1st century BCE onward pushed extraction to a new scale. The stone later took the name portasanta after builders used it for the door jambs of the Holy Door at St. Peter's Basilica in Rome, centuries after the ancient quarry closed. Roman villas favored it for opus sectile inlay floors laid out in alternating colored panels.

What happened here

The rock is worked in benches from the top down, so that gravity does the moving. Channels are cut around a block with a pick, then it is split from the bed with iron wedges driven into a line of holes, sometimes with wooden wedges soaked to swell. Blocks are dressed roughly on the spot — no one hauls waste — and marked with the quarry, the gang, the date and the consular year, which is how the empire keeps track of what it owns. Sledges, rollers and ox teams take them to a river or the sea, because moving stone overland is the expensive part. Fine marbles are imperial monopolies. Abandoned faces still show the last unfinished cut, stopped mid-job and never resumed.