Length:1-4mm,5-8mm color:grey,white Main use: brake block ... )Mohs hardness scale6Maximum Operation Temperature1450 centigradeArea of OriginHeBei province Feature: 1. Main chemical content is SiO2, MgO, crystal water etc. 2 ... tough ,tensile and soft with better luster and spinnability. Application: 1.It could be used in thermal insulation products. 2.It ...