Pumice or Tufa/Travertine

Pumice (if igneous) or Calcareous Tufa (if sedimentary)

Rock Type: igneous/sedimentary

Light-colored, highly vesicular (porous) texture. Hardness varies depending on exact composition but is generally moderate. Pitted surface.

Pumice forms from highly vesicular volcanic glass. Tufa/Travertine precipitates from carbonate minerals in ambient temperature water bodies.

Pumice is used as an abrasive, in lightweight concrete, and for landscaping. Tufa is used in landscaping and architecture.

Pumice is so light it can often float on water.

Identified by its porous, pitted structure and relatively light weight compared to its size.

Identified on: 4/26/2026

Mode: Advanced