[1][2] The complex is chiefly made up of peralkaline nepheline syenite and is rich in exotic minerals.

[1] Rocks of the complex intruded into the Paleoproterozoic-aged Växjo granites of the Transscandinavian Igneous Belt.

[2] In 1968 Harry von Eckermann published his investigations on the complex defining its boundaries and confirming the view of it as an intrusion.

[7] Since 2009, the Canadian company Tasman Metals has owned the mining rights and explored for rare earth elements in the Norra Kärr area.

[8][1] In February 2016 the supreme administrative court of Sweden withdrew Tasman's exploitation concession for Norra Kärr.