variety of silica containing microcrystalline quartz
chert详细解释
chert n.（名词）A variety of silica that contains microcrystalline quartz.燧石：含微小晶状的石英的各种硅石A siliceous rock of chalcedonic or opaline silica occurring in limestone.硅石：出现在灰岩中的玉髓或蛋白色硅石 来源：[Origin unknown] [词源不详] 【引伸】 chert.y adj.（形容词）
