... 's request 2.ISO9001:2000,ISO14001:2004 Sand rock is a type of high quality natural rock without light pollution or radiation hazard ... around 15%;C.goethite around 18%;D.miscellaneous over 10%Sand rock,sound insulation,moisture absorption,no weathering outside,no dissolving in ... water moss and easy clean. yellow sand rock1Size 300×200cm,300×100cm,200×100cm,30×30cm,etc ...