名词石英岩，硅岩
1. 石英石：玛瑙 (松香黄) Onyx | 石英石 Quartzite | 沙石 Sandstone
2. 硅石：quartz tube 石英管 | quartzite 硅石 | quasi isotropy 伪蛤同性
3. 硅岩：quartz porphyry 石英斑岩 | quartzite 硅岩 | quaternary hybrid 四祖杂种
1. Among the massive limestone blocks toppled in the fourth century was a huge quartzite block with an engraving of a pharaoh.
noun
1. hard metamorphic rock consisting essentially of interlocking quartz crystals