Poros stone is a lightweight, soft,

marl Marl is an earthy material rich in carbonate minerals, Clay minerals, clays, and silt. When Lithification, hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. M ...

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

that was widely used in construction and statues of

Ancient Greece Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically r ...

. There is no precise definition of the term, although its roots go to antiquity, when it was used to designate any porous building rock, regardless of its origin, mostly in contrast with

marble Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO3) or Dolomite (mineral), dolomite (CaMg(CO3)2) that have recrystallized under the influence of heat and pressure. It has a crystalline texture, and is ty ...

. In the 20th century the archeologists continued to use the term in the similarly loose way: " asmade to include almost all light-coloured stones" that were not definitely marble or hard limestone. The stone is one of the chief formations of the

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

(

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Peloponnese The Peloponnese ( ), Peloponnesus ( ; , ) or Morea (; ) is a peninsula and geographic region in Southern Greece, and the southernmost region of the Balkans. It is connected to the central part of the country by the Isthmus of Corinth land bridg ...

, making a common construction stone there. Even when hardened by exposure to the elements, is much more readily cut with a knife than is an ordinary limestone. The ease of working with is the reason for its extensive use as a building stone, especially for foundations and other architectonic parts that are not exposed to view.

Ancient term

The Greek geographer Pausanias uses the term "" to describe the material of the Temple of Zeus at Olympia, which was built of local shell limestone,

Theophrastus Theophrastus (; ; c. 371 – c. 287 BC) was an ancient Greek Philosophy, philosopher and Natural history, naturalist. A native of Eresos in Lesbos, he was Aristotle's close colleague and successor as head of the Lyceum (classical), Lyceum, the ...

(and

Pliny the Elder Gaius Plinius Secundus (AD 23/24 79), known in English as Pliny the Elder ( ), was a Roman Empire, Roman author, Natural history, naturalist, and naval and army commander of the early Roman Empire, and a friend of the Roman emperor, emperor Vesp ...

, who borrows the description) declares it to be a less dense variant of

Parian marble Parian marble is a fine-grained, semi translucent, and pure-white marble quarried during the classical antiquity, classical era on the Greece, Greek List of islands of Greece, island of Paros in the Aegean Sea. A subtype, referred to as Parian ' ...

Herodotus Herodotus (; BC) was a Greek historian and geographer from the Greek city of Halicarnassus (now Bodrum, Turkey), under Persian control in the 5th century BC, and a later citizen of Thurii in modern Calabria, Italy. He wrote the '' Histori ...

also contrasts coarse with fine marble.

Archeological term

Henry Stephens Washington (a

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

with a major interest in

classical studies Classics, also classical studies or Ancient Greek and Roman studies, is the study of classical antiquity. In the Western world, ''classics'' traditionally refers to the study of Ancient Greek and Roman literature and their original languages ...

) declared in 1923: Washington describes the differences between and regular limestone as the former being very finely arenaceous or

y; most often of a pale cream color, also light yellow or light gray; somewhat granular but rather soft and friable and easily cut with a knife, especially when first exposed in the quarry (similar to the

volcanic tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

s of

Roman Campagna The Roman Campagna () is a low-lying area surrounding Rome in the Lazio region of central Italy, with an area of approximately . It is bordered by the Tolfa and Sabatini mountains to the north, the Alban Hills to the southeast, and the Tyrrh ...

in this last quality, while having nothing in common otherwise). Hadjidakis et al., while reviewing the ancient quarries, use the term in its ancient sense, to designate any low-density rock, regardless of its petrographical classification.

References

Sources

* * * * {{cite book , last=Frazer , first=J.G. , title=Pausanias's Description of Greece , publisher=Macmillan and Company, limited , issue=v. 3 , year=1913 , url=https://books.google.com/books?id=NcPNAAAAMAAJ&pg=PA503 , access-date=2023-09-18 Ancient Greece Building stone Limestone