From our archives…
Enamel is Glass – But, What is Glass?
by: Woodrow Carpenter
In the beginning, there was glass. Glass was created or formed along
with our planet Earth. Glass was here - waiting to be discovered by
humankind – as early as 75,000 BC, to use as spear points, daggers
and crude axes. We are referring, of course, to natural glass rather
than human made glass.
Volcanoes emit lava, which may cool as a glass (obsidian) or
crystallize into rock masses, depending on composition and rate of
cooling. In Yellowstone National Park, there is a great mass of
volcanic glass, nine miles long and five miles wide, in which there
are only occasional traces of crystalline forms. When volcanic glass
is impregnated with steam, it forms a glass of cellular character
known as pumice. In the islands of Lipari in the Mediterranean,
there are two mountains of pure pumice…