The white unit of Arequipa Airport Ignimbrite is a pyroclastic rock that emerges in the deposits of Arequipa and is used as a construction material since colonial times and locally called "sillar"or "ashlar". The thermal conductivity and thermal diffusivity measured according to ASTM C 177 and Ångstrom's method were 0.27 W/mK and 5.67×10-7 m2/s, respectively. The compressive strength and water absorption were 8.92 MPa and 17.2 %. The main crystalline phases of the ignimbrite are plagioclase, cristobalite, sanidine and biotite. The white ignimbrite has good thermal insulation and good mechanical properties.