Løvøya

Thorium was discovered and identified for the first time on Løvøya.

In 1828, while the priest in Brevik was hunting ducks on Løvøya, he found a brownish mineral that was new and unknown to him. He took a sample and sent it to the renowned chemist J. J. Berzelius in Sweden, who, after careful examination, determined that it was a completely new mineral. And not only that-the new mineral contained a new, previously unknown element! The mineral was named thorite, and the new element was named thorium. Both names were inspired by the Norse god of natural forces, strength, and fertility-Thor.

The man who found the new mineral

Hans Morten Thrane Esmark became interested in natural science at a young age. His father, Jens Esmark, taught at the Mining Academy in Kongsberg and was one of Norway’s prominent geologists. However, Hans Morten chose theology over mineralogy to ensure a secure job. As a priest in Brevik, he discovered that he could combine paid work with his hobbies. Esmark collected minerals, studied plant diseases, described new fossils, and was engaged in local economic development. He also became Brevik’s first mayor.

Esmark is known for several other mineral discoveries, including aegirine. This mineral also received a name suggested by Berzelius, once again after a Norse god, the sea god Ægir. The mineral was found on the islet Låven, on the south side of Stokkøya. Låven is a protected natural monument due to its mineral wealth, and collecting minerals or otherwise damaging the deposits is prohibited.

Thorite fever

Around 1890, it was discovered that if cotton mantles in gas lamps were impregnated with thorium, the lamps would burn with a brilliant white light. People flocked to find thorium, and there was an intense search for thorite in the Langesundsfjord. The mineral fetched a high price; in today’s money, some believe the price per kilogram could reach tens of thousands of kroner. However, the "fever" quickly subsided-new and more accessible sources of thorium were found, and the introduction of electricity eliminated the need for gas lamps. At the same time, it was discovered that thorium is a radioactive element.

Esmark (1801–1888) served as priest in Brevik from 1826 to 1849. Against his will, he had to leave Brevik after being appointed to Ramnes in Vestfold, but his scientific contributions in Brevik became important for Norway’s scientific history.

In 2019, in connection with the 150th anniversary of the Periodic Table, thorium was named Norway’s national element. The radioactive element was first identified in a rock sample from this small island, Løvøya in Porsgrunn municipality.