What chemical properties of glass would allow it to be recycled as sand on a beach?

Answer 1

Basically, sand and glass are different forms of the same compound, SiO2.

Answer 2

There is no chemical property responsible for glass being recyclable. It is a physical property.

If you grind glass into fine sand, well it becomes fine sand. The chemical properties remain intact. Heating glass will just melt it. That is another physical property.