Types of Glass
Glass, Characteristics
Glass is made from silica and other materials. It is
not affected by the weather nor by most chemicals. Most
glassware is easily broken by blows; sometimes hitting it
hard only damages the glass invisibly so that later it
shatters from just a light impact. Glass is blown or
molded into many shapes for decorative items, and for
beverage glasses and other eating and serving dishes.
Crystal is made from the same basic material as glass
but lead is added to fine crystal which adds sparkle and
strength.
Heat-resistant glassware has been treated to withstand
high temperatures. Such utensils may break when subjected
to sudden changes in temperature. Ovenware is not suitable
for top-of-range use as it is not made to stand direct
flame heat.
Glass ceramics are made from hard crystalline
materials which were first used on missile nose cones.
Glass ceramics are used for range tops, counter tops,
dinnerware, and cookware. The cookware may be used in the
oven, under the broiler, on the stove, or in the microwave
oven. They are guaranteed by the manufacturer not to break
from temperature change.