Metals Used to Impart Colour to Glass
                    Substance Added                  Colour
                    Antimony Oxides                  White
                    Cadmium Sulfide                  Yellow
                    Carbon Oxides                    Amber Brown
                    Chromic Oxide                    Emerald Green
                    Cobalt Oxide                     Blue-Violet
                    Copper Compounds                 Blue, Green, Red
                    Gold Chloride                    Red
                    Iron Oxide                       Greens and Browns
                    Lead Compounds                   Yellow
                    Manganese Dioxide                Purple
                    Nickel Oxide                     Violet
                    Sulfur                           Yellow-Amber
                    Tin Compounds                    White
                    Uranium Oxide                    Fluorescent Yellow, Green
Types of glass                                         them from flying in all directions. It is used
                                                       where broken glass might cause serious
Soda glass or soda-lime glass is prepared by           injuries, as in automobile windshields.
heating sodium carbonate and silica. Uses:
making windowpanes, tableware, bottles and             Optical glass is used in eyeglasses,
bulbs.                                                 microscopes, telescopes, camera lenses, and
                                                       many instruments for factories and
Colored structural glass is a heavy plate              laboratories. The raw materials must be pure
glass, available in many colors. It is used in         so that the glass can be made almost flawless.
buildings as an exterior facing, and for interior      The care required for producing optical glass
walls, partitions, and tabletops.                      makes it expensive compared with other kinds
                                                       of glass.
Plate glass It is made by floating a layer of
molten glass over a layer of molten tin. So, it        Pyrex glass or borosilicate glass is highly
is thicker than ordinary glass. Uses: shop             heat resistant. Uses in Laboratory equipment,
windows, doors, etc.                                   ovenware, etc.
Bullet-resisting glass is thick, multilayer            Photochromic glass darkens when exposed to
laminated glass. This glass can stop even              ultraviolet rays and clears up when the rays are
heavy-caliber bullets at close range. Bullet-          removed. It is used for windows, sunglasses,
resisting glass is heavy enough to absorb the          and instrument controls.
energy of the bullet, and the several plastic
layers hold the shattered fragments together.          Chalcogenide glass is made up of elements
Such glass is used in bank teller windows and          from the chalcogen group, including selenium,
in windshields for military tanks, aircraft, and       sulfur, and tellurium. The glass is transparent
special automobiles.                                   to infrared light and is useful as a
                                                       semiconductor in some electronic devices.
Laminated safety glass is a “sandwich” made            Chalcogenide glass fibers are a component of
by combining alternate layers of flat glass and        devices used to perform laser surgery.
plastics. The outside layer of glass may break
when struck by an object, but the plastic layer
is elastic and so it stretches. The plastic holds
the broken pieces of glass together and keeps