Ask A Scientist General Science Archive

Question:  How do you make glass?
 bob w whitbeck

Answer:
I only know a bit about this subject.  The basic building block of glass
is silica which is the major component of everyday sand.
It is possible to make glass by melting sand.  Natural glass can even
be found near volcanos and is called obsidian.  This was sometimes used to
make tools and weapons in the same way as flints and cherts have been.
Glasses of differing characteristics are produced by removing impurities
and by adding specific compounds.  The existence of different types of glass
is a major obstacle to economic glass recycling.  Most communities that
have recycling programs will not accept light bulbs, window glass, mirrors
and perfume bottles beause this glass can contaminate food and beverage
container glass.  Some of the incompatibilities are differences in melting and
solidification temperatures and changes in strength and flexibility.  Mixed
glass waste can be used as a supplement in road repair but I know of no other
use.  Call your local recycling manager and ask!
 michael b lomonaco