Physical state : this produce is made of natural silica sand by the advanced processes of water scrubbing and reelecetion . natural silica sand has the naturally founded grain shape and uniform particle size and takes on brown - white or off - white color 物理状态：本产品经天然硅砂水洗，重选等工艺加工而成，天然硅砂具有天然的滚圆粒形和均匀的粒度，呈褐白色或灰白色。
