Encara no tenim significats per a "compose of silica".
1Amygdules are commonly composed of silica.
2In silicious sponges the spicules are composed of silica, and are generally deposited around axial rods in concentric layers.
3Those that are composed of silica and soil are called "barrows" in high-flown language, while the simple heaps of stones are "gals-gals."
4The analysis of lapis lazuli represented it to be composed of silica, alumina, and soda, three colourless bodies, with sulphur and a trace of iron.