Monday, November 16, 2020

CONSTRUCTION TECHNIQUES, STONES FOR BUILDINGS, MARBLES AND HARD ROCKS IN ANCIENT ROME


CONSTRUCTION TECHNIQUES

OPUS CAEMENTICIUM

Mix of mortar and caementa, i.e. rough stones or fragments of broken stone. The mortar in turn consists of lime mixed with sand or pozzolan

Lime was obtained by burning in ventilated furnaces (which were known as calcare) limestone or marble, made of calcium carbonate. Limestone or marble, due to the heat, would turn into calcium oxide or "quicklime", which, with the addition of water, would become "slaked lime" and diluted for use took the name of grassello

OPUS SILICEUM (or polygonal)

Irregular cut stone blocks stuck into each other without mortar

OPUS QUADRATUM

Regular blocks of parallelepiped shape arranged in horizontal rows (isodomic rows)

In use since the Archaic period, end of the seventh/beginning of the sixth century BC. Since the fourth century BC it would be consisting in rows alternately arranged by long and narrow side

Examples: Roman walls of the sixth century in cappellaccio stone, part of the foundations of the Temple of Capitoline Jupiter

OPUS INCERTUM

First two decades of the second century BC. Small tufa blocks (tufelli) of pyramidal shape immersed in the core of the wall with the visible side of irregular shape

Examples: Temple of Magna Mater, Porticus Aemilia

OPUS QUASI RETICULATUM

An evolution of opus incertum tending to opus reticulatum

Examples: Source of Juturna, House of Griffins, the second phase of the Temple of Cybele

OPUS RETICULATUM

Perfectly regular arrangement of small tufa rocks (tufelli) with square base forming a net-like pattern. It was common from 100 BC up to the Julio-Claudian period when the use of brick starts to prevail

Examples: Horrea Galbana, Theatre of Pompey

OPUS MIXTUM

It was common from the Flavian until Hadrian period (69/117). It ended during the Antonine period

Crosslinked structure at first, in the Republican period, reinforced with horizontal bands of brick or tiles. During the empire it was more like nets of square little blocks framed in squares made of bricks

OPUS TESTACEUM (or Opus Latericium)

Bricks or shingles. Since the end of the republican period onwards. In the first century BC it was common to mark the consular date on bricks. From 123 AD with Hadrian it became mandatory until 164, for example in the Castra Praetoria

OPUS SPICATUM

Floor in bricks arranged in a herringbone pattern

OPUS VITTATUM (or Opus Listatum)

Horizontal bands of bricks alternated with parallelepiped- shaped tufa stones arranged in horizontal bands. It was common since the beginning of the fourth century AD

OPUS SECTILE

Inlaid marble for floors and walls

OPUS TASSELLATUM

Mosaic formed by cubical tiles, of different sizes, but common in shape, in black and white

OPUS VERMICULATUM

Eastern origin, consisting of tiles sometimes very tiny, in vivid multicolour, who had the most diverse forms to suit the design


STONES FOR BUILDING

CAPPELLACCIO

Granular tufa, brittle and gray from the soil of Rome. Archaic period (600/400 BC)

Examples: ancient parts of the Servian Walls, Temple of Capitoline Jupiter, archaic cisterns on Palatine Hill

LATERIZIO

Laterite Bricks

Typical Roman bricks of the imperial period. They were made with clay, decanted and purified in water and degreased with the addition of sand, according to a procedure similar to that used in the ceramic, in particular for that of common use, such as the amphoras for transport of liquids

The clay thus prepared was then processed using wooden molds, which gave the desired shape. The bricks were then dried for a few days, protected from direct sunlight and, eventually, baked in kilns, where temperatures could reach 1000 °

The manufacture of bricks was a real industrial activity. Its production facilities (figlinae), located generally in the vicinity of clay deposits and along the rivers that allowed easy transport of materials, were generally owned by important people, often related to the imperial family

It is possible to know about the workshops from the use of marking on some of the bricks, while they were still wet, a brand which could have the date and other informations

The shape of the brand, the "brick mark", changed in different periods: initially rectangular, with text on one line, it became semicircular under Claudius (41/54), then moon-shaped with Domitian (81/96) and round in the early third century

With Hadrian (117/138) it was introduced the mandatory use of mark the date of manufacture (consular date). To the time of Theodoric (King of Italy 493/526) date the last known brick marks, circular or rectangular

PEPERINO (Lapis Albanus)

Gray tufa ash-colored from the quarries in Marino, used from the fourth/third century BC

Examples: Aqueduct Acqua Marcia, Sepulchre of the Scipios, Temples of the Forum Holitorium, Wall of the Forum of Augustus, Temple of Antoninus and Faustina, Temple of Magna Mater

SPERONE STONE (Lapis Gabinus)

Tufa similar to peperino but less fine-grained with more residue

Example: the arch of the Cloaca Maxima to let sewage flow into the Tiber River

TRAVERTINE (Lapis Tiburnus)

Sedimentary limestone from Tivoli. It was used since the second century BC

Examples: Theatre of Marcellus and Colosseum

TUFA OF THE ANIENE RIVER

Reddish from quarries of Tor Cervara. Used since about 160 BC

Examples: Aqua Marcia, Milvius Bridge

TUFA OF GROTTA OSCURA

Porous, yellowish from the territory of Veii. Used since the conquest of Veii in 396 BC and even before, until the second century BC

Examples: Stele of Lapis Niger, Walls of the fourth century BC, Temples C and A of Largo Argentina, Basilica Aemilia, Temple of Veiove, Aemilius Bridge, Milvius Bridge

TUFA OF FIDENE

Yellowish with black residue from the quarries at Castel Gubileo. Perhaps used since the conquest of Fidenae in 426 BC until the second century BC

Examples: substructure walls of Palatine Hill and Capitol HIll, republican walls of the fourth century BC, Temples of S. Omobono, Temples C and A of Largo Argentina

TUFA OF MONTEVERDE

Light brown with multicolored residue. Quarries at the foot of the Janiculum Hill and in the Magliana area. It was used from the second century BC on


MARBLES AND HARD ROCKS

AFRICAN (marmor luculleum)

Various colors and veins, especially red and black. From Teos in Asia Minor (Turkey), introduced by Lucullus

BASANITE (lapis basanites) or bekhen stone

It exists in two versions: a siltstone (fine-grained) and a greywacke (slightly more coarse-grained): both are of metamorphic origin, color uniform dark (dark gray to gray-green)

The quarries are on rock walls on both sides of Wadi Hammamat in the Eastern Desert of Egypt

BIGIO MORATO (lapis niger) or ancient Numidian black marble

Intense black tones and fine grain. The quarries were located in the town of Ain el Ksir in Tunisia, not far from those of ancient yellow marble

Examples: "Two centaurs" at the Capitoline Museums or "Victory of the Simmaci" at the Centrale Montemartini

CIPOLLINO (marmor carystium)

With parallel bands streaked ranging from white-green to dark green. From Carystos in the southeast of Euboea in Greece

It is called cipollino (small onion in Italian) for the onion smell that emanates when this type of marble is cut

Examples: columns of the Temple of Antoninus and Faustina

ANCIENT YELLOW (marmor numidicum)

Intense yellow with dark yellow and dark red veins from Chemtou in Tunisia (ancient Numidia)

Ancient yellow is Giallo Antico in Italian

GRANITE OF OBELISKS

Red or pink. From Syene (now Aswan) in Egypt

GRAY GRANITE OF THE FORUM

From Mount Gebel Fatira (Mons Claudianus), in the Eastern Desert of Egypt

A variation with finer grain comes from places of extraction sites within easy reach (Wadi Umm Huyut). It takes its name from the many column shafts in the Forum of Trajan

IMEZIO (or Hymettus Marble, Onion Marble)

The Roman name (Marmo Cipolla = Onion Marble) was given, as with the Proconnesian marble or the Cipollino marble, for the bituminous smell emanating at the time of fracture. For this reason and also for the look these marbles are difficult to distinguish

The quarries are located on Mount Hymettus, about 11 km (6.8 miles) from Athens

It has been used in the construction of buildings of Athens. It was definitely used by the fourth century BC

In Rome it was introduced in the early years of the first century BC by the consul Lucius Crassus and used especially in architecture. From the period of Augustus (27 BC/14 AD) the popularity of some white marbles was decreasing after the beginning of the large-scale exploitation of the Lunensis marble (Carrara marble)

Examples: Arch of Trajan in Ancona, ten columns in the portico outside on the left of the Basilica of St. Paul, column in front of St. Mary Major, the column of St. Peter in Chains

LUNENSIS

From Carrara. The quarries were opened by Julius Caesar and became imperial property at the time of Tiberius (98/117)

PARIAN

White, coarse-grained. It was the most widely used marble in ancient statuary. From the island of Paros in the Cyclades Islands

PAVONAZZETTO (marmor phrygium or synnadicum)

Chalky white marble with elements of purple purplish veined, dark purple, like the peacock's tail

It is also known as Phrygian marble, for coming from Docimia in the Phrygia region, near Synnada corresponding to the current İscehisar in Turkey

PENTELIC

White, fine grain. From Mount Pentelicus 15 km (9.3 miles) northeast of Athens

RED PORPHYRY (lapis porphirites)

Hard, red-purple dotted with small white specks. It was possible for the Romans to quarry it after the conquest of Egypt by Augustus in 31 BC

It came from quarries owned by the emperor on Mons Porphyrites or Mons Igneus, a mountain range known today as Gebel Dokhan west of Hurghada, in the Eastern Desert of Egypt

It is a kind of marble very hard and difficult to carve, already used by the Egyptian kings and highly regarded for his fiery red color, typically associated with the imperial dignity

GREEN PORPHYRY or SERPENTINE (lapis lacedaemonius)

Deep green with light green crystals from the Peloponnese near Sparta

PORTASANTA (marmor chium)

Dark gray base with reddish spots and streaks from light red to bloody red. From the island of Chios in the eastern Aegean Sea

The name originates from the marble pillars of the Holy Door (Porta Santa in Italian) of St. Peter's Basilica

PROCONNESIAN

White color, with shades of cerulean, uniform or with bluish-gray veins in large crystals. The quarries were located in the Proconnesus island, today island of Marmara in the Sea of ​​Marmara in Turkey

ANCIENT RED

Deep red. Ancient Red is Rosso Antico in Italian. From the quarries of Tenaro, Cape Matapan in the Peloponnese

ANCIENT GREEN

Green background with dark gray, white, black and dark green inclusions. Ancient Green is Verde Antico in Italian. From near Larissa in Thessaly (Greece)

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