| |||
pebble; silica | |||
chert; hornstone; flint; silex | |||
boulder flint | |||
crushed or broken stone | |||
| |||
pebblestone; gravelstone; min. silex |
silex : 14 phrases in 8 subjects |
Coal | 2 |
Construction | 2 |
Earth sciences | 1 |
Environment | 1 |
General | 2 |
Industry | 3 |
Medical | 2 |
Metallurgy | 1 |