Pozzolana (a form of lava) is an inorganic pozzolanic material with hydraulic properties.  Widely available around the world, in Greece it can be found on the volcanic island of Santorini. Pozzolana’s properties have been well-known since antiquity and it was known to be an ingredient in the cement used by the Romans -a material on a par with modern cements- which was a mix of pozzolana, hydrated lime and sand.

Nowadays, pozzolana is used to reinforce mortars because when it joins with lime it forms sand-lime compounds that harden the mortar in the presence of water ensuring highly durability, hydraulic properties and a very long life. Pozzolana is a favourite with archaeologists and conservators because it can be used to manufacture mortars and restoration grout. It comes in various grain sizes and can be purchased in normal-sized bags or 1 ton bigbags.