On March 26, 1895, Scottish chemist Sir William Ramsay isolated helium on Earth by treating the mineral cleveite (a variety of uraninite with at least 10% rare earth elements) with mineral acids.
La data de 26 martie 1895, chimistul britanic Sir William Ramsay a izolat heliul prin tratarea unui mineral numit cleveit (o varietate a uraninitului ce conține cel puțin 10% pământuri rare) cu acizi minerali.