1.Size:5-325mesh1-3,2-4,3-5mm 2.Color:grey 3.Origin:Henan,china 4.MOQ:20TONS ... Vitrified micro bubbles, Brilliant expansion perlite,perlite powder 1.Perlite Feature: poisonless,tasteless,staleless,nonconbustible,acid-resistant,alkali ... .3-0.6mm 0.3-1mm 1-2.8mm 1-2.5mm 1-3mm 2-4mm 3-5mm etc3 ... /ccAl2O312-16Vickers hardness5.5-7Fe2O30.1-2Softening point890-1090 °C CaO0.15-1.5Melting point1280-1350 °C Na2O4 ...