Ultrapotassic igneous rocks

Ultrapotassic igneous rocks are a class of rare, volumetrically minor, generally ultramafic or mafic silica-depleted igneous rocks.

While there are debates on the exact classifications of ultrapotassic rocks, they are defined by using the chemical screens K₂O/Na₂O > 3 in much of the scientific literature.^[1] However caution is indicated in interpreting the use of the term "ultrapotassic", and the nomenclature of these rocks continues to be debated, with some classifications using K₂O/Na₂O > 2 to indicate a rock is ultrapotassic.