Uses of CaCO3 from prehistory to the Middle Ages

40,000 – 10,000 BC. Cave paintings used calcium carbonate pigments

The major prehistoric use was not of the Chalk itself, but of the flints within the Chalk, which are known to have been used as tools by prehistoric man.

However, calcium carbonate has been detected in nearly all prehistoric cave paintings in the period between 40,000 and 10,000 BC, though it was only right at the end of this epoch that chalk and limestone powders were actually used by the caveman artists.

100AD – 5th Century. Calcium carbonate used to construct roads

Chalk, flint and gravel were used by the Romans to construct road systems. They utilised chalk in many other ways, chalk was thought to have been used in coffins to preserve bodies and was also used in cosmetics worn by Roman women.

Anglo-Saxon Britain – Middle Ages. Chalk used as a fertilser

In Roman Britain, Anglo-Saxons times and in the Middle Ages, chalk was applied to the land as a fertiliser – a practice still routinely carried out by farmers today. Regular Calcium carbonate applications help reduce soil acidity and help optimise conditions for crop growth. Old Norman leases often contained covenants to ensure that chalk was regularly applied to the land and a statute of Henry III in 1225 gave every man the right to sink a marl pit on his own land.

Other older uses for chalk in the Middle Ages include it being used for medicinal purposes in the fight against scurvy, probably unsuccessfully, and in the mid to late 14th century Welsh market traders used to try to pass chalk off as a hard cheese on unsuspecting customers, hence the popular term 'chalk & cheese'!