Mineral Relocation

Photo: Thor Seng-Liew / New Scientist
Photo: Thor Seng-Liew / New Scientist

Limestone is the key ingredient in cement, and is quarried around the world for mixing into one of the world’s most popular building materials. Limestone is composed mainly of CaCO3, calcium carbonate.

Coincidentally, the shells of the small snails shown above – like most gastropod shells – are also composed mostly of CaCO3. These little lopsided wonders, part of a small group of newly-identified members of the Plectostoma genus, live mostly on limestone hills in Malaysia, Sumatra and Thailand. Thor-Seng Liew of the Naturalis Biodiversity Center in Leiden, the Netherlands, who describes them in his recently published paper, has dubbed them ‘microjewels‘.

Unfortunately for them and their Plectostoma brethren, limestone for cement is vastly more popular among humans that calcium carbonate found in snail shells, no matter how asymmetrically lovely and unusual.

Ten of the 31 micro-landsnails listed in the research have been assessed to be critically endangered – or rather, nine are critically endangered, one is already extinct. The researchers are submitting all of them for classification and possible protection under the IUCN Red List.

To be fair, the limestone hills themselves are disappearing at a rapid rate, their CaCO3 headed for cement to build new hills in the form of buildings, somewhere else, and without the delicate CaCO3 of their former inhabitants, the microjewel snails.

Or rather, with their CaCO3, but minus the snails.

Limestone extraction at Bukit Panching, Malaysia, 2003-2010. The top image was taken after the 300 meter hill had already been mostly removed. The lower image shows what is now a lake where the hill once stood. Source: SiputKuning
Limestone extraction at Bukit Panching, Malaysia, 2003-2010. The top image was taken after the 300 meter hill had already been mostly removed. The lower image shows what is now a lake where the hill once stood.
Source: SiputKuning