perliteIts main components are massive, porous, pumiceous perlite, with water-containing sanidine, phenocrysts of quartz, microcrystals, various forms of crystallites, cryptocrystalline minerals, hornblende, etc.Arc - shaped cracks, the fracture surface is irregular in shape, with pearlescent luster, it shows oily luster after weathering, and the streak is white.Flowing structure is well-developed2～6
PitchstoneThe main components are perlite, hydrolyzed perlite and hydrated perlite, containing a small amount of sanidine and white tuffaceous material, with an irregular distribution.The fracture is conchoidal, with resin luster, and the streak is white.6～10
ObsidianThe main components are obsidian, obsidian porphyry and hydrated obsidian, containing a small amount of quartz and feldspar phenocrysts, and a very small amount of opaque magnetite, corundum and so on.The fracture is flat or conchoidal, partially uneven, with vitreous luster, and greasy luster after weathering, with white streaks.<2
perlite<10≥15First-class product
Devitrified perlite10～407～15II. Third-grade products
Strong devitrified perlite>40～65<7Ore clip
