Damtjern

The rock keeps a dialect spelling of a Norwegian lake name that the maps stopped using.

Waldemar Christofer Brogger named the rock in 1921 in Die Eruptivgesteine des Kristianiagebietes, after the small lake Damtjern in the Oslo rift. He wrote both the lake and the rock with kj, giving Damkjern and Damkjernit, an older dialectal form of Norwegian tjern, meaning tarn. The standardized place name is Damtjern, which is why the rock now has two spellings in the literature.

Two spellings of one rock name survive in petrology because a Norwegian lake was respelled after 1921.

Brogger coined the rock name in 1921 as Damkjernit, using the dialect spelling of the lake Damtjern in the Oslo rift. Once the place name was standardized with tj, petrologists began writing damtjernite to match the map. Both forms appear in current literature on alkaline rocks and their associated carbonatites.