Calcium Carbonate, Brazilian mussels and Robin Hood’s Bay Limpets

You might ask, what do Calcium Carbonate, Brazilian mussels and Robin Hood’s Bay Limpets have in common?

Let’s start with what calcium carbonate is. It forms approximately 4% of the rocks found on the Earth, mainly in the forms of chalk, limestone and marble. The uses of calcium carbonate are wide and varied; from relieving heart burn as antacid tablets, to the construction of roads and buildings, to the deacidification of rivers and fields.

The majority of this calcium carbonate is mined. However, while researching a topic involving calcium carbonate, Fyling Hall’s Year 12 chemist, Lydia Batty, came across an article by Hamester et al (2012), on how, in Brazil, discarded mussel shells are being recycled to obtain the calcium carbonate present in their shells. This got the AS group thinking about our own rocky sea shore and whether our local limpets contain a similar amount of calcium carbonate in their shell.

After careful searching of the beach, (please note that no animals were harmed in this research!), a number of likely specimens were obtained and taken back to the lab for further investigation. After, much crushing and reactions involving hydrochloric acid, the AS students were able to use their newly acquired titration skills to analyse the amount of calcium carbonate present. In turns out that our local limpet has much in common with the Brazilian mussel, with both their shells containing approximately 95% calcium carbonate.

Dr Ian Richardson, Head of Chemistry