<human>:  Could Quartz be useful to humans if plants died off and there was no oxygen?
<bot>: Yes, Quartz mineral composed of silicon and oxygen atoms in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two Plants produce oxygen which is needed by humans to survive. Quartz is a hard mineral substance made of several elements. Quartz is composed of silicon and oxygen. Quartz can be melted at high temperatures. So Quartz could be useful to humans.