Perlite is a useful thermal insulator, although it has weaknesses compared to other materials.
Vermiculite Insulation And The Home Inspection
Perlite - Insulation Products - Perlite Canada
Insulation - Perlite Institute
Insulation and Energy > General - Inspection Gallery - InterNACHI®
What type of insulation?? - Structural Inspections - InterNACHI
Mechanical Insulation, Perlite Insulation
Perlite as an Insulating Construction Fillers · Dicalite
Thermal insulation - PERLITE - Inpro - perlite / loose / for ceiling
White powder covering insulation in the attic? - Interior
expanded perlite board insulation/insulation board expanded
What type attic insulation is this? - Interior Inspections
Insulation and Energy > General - Inspection Gallery - InterNACHI®