Tuffite

According to the IUGS definition, tuffite contains 75% to 25% volcanic (epiclastic) material.

The classification in the IUGS recommendation is based on the definition established by Schmid (1981).

Some other, mostly older, sources state that tuffite may contain 10% to 50% volcanic material.

Nonvolcanic material may consist of terrigenous, chemical precipitates, or organogenic components.

Quartz or mica and an admixture of carbonates, siliceous rock fragments, or organic remains may be common.