... Black 3.Size:3-5mm 4.USD140-180/MT 5.Natrual mine Size:1-3mm,3-5mm,5- ... 7mm,7-10mm,5-10mm;1-2cm,2-4cm,3-5cm,4-8cm ... ,5-10cm,etc 1.Chemical Composition: SiO2CaOMgOFe2O3FeOAl2O3TiO2K2ONa2O53.82%8.36%2.46%9.08%1 ... .12%16.89%0.06%2.30%2.55% 2.Properties:1.It has ... 240*190)Hollow ratio(%)48/(390 *240 *190)4.Usage:Lava is used in construction,irrigation works, ...