| 2505.10 | 000 | Silica sands and quartz sands |
| 25.06 | | Quartz (other than natural sands); quartzite, whether or not roughly trimmed or merely cut, by sawing or otherwise, into blocks or slabs of a rectangular (including square) shape |
| 2506.10 | 000 | Quartz |
| 2506.20 | 000 | Quartzite |
| 7002.31 | 000 | Of fused quartz or other fused silica |
| 7017.10 | 000 | Of fused quartz or other fused silica |
| 7104.10 | 000 | Piezo-electric quartz |
