Poros stone
Poros stone is a lightweight, soft, marly limestone that was widely used in construction and statues of Ancient Greece. 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. In the 20th century the archeologists continued to use the term in the similarly loose way: " made 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 in Greece and it occurs at many places in the Peloponnese, making a common construction stone there.
Even when hardened by exposure to the elements, is much more readily cut with a knife than 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 declares it to be a less dense variant of Parian marble. Herodotus also contrasts coarse with fine marble.Archeological term
declared in 1923:Washington describes the differences between and regular limestone as the former being very finely arenaceous or marly; 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.
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.