Madison County  Stained Glass

Glass is made mostly from the mineral silica. Silicia can be sand, quartz crystal, or flint, however the most common is sand. Sand requires an extrmely high melting point  3600º F so to lower the temperature ingredients like soda (sodium carbonate) are added. Soda makes the glass water-soluble, or able to be dissolved in water, so other ingredients, also called flux, are added to counteract. One example includes lime which helps provide strength, stability, and hardness. The formula for a typical window might include: 50% silica sand, 15% soda ash, 10% salt, 10% lime, and other ingredients for color. 

There are many different types of glass but the most common is soda. Soda glass makes up a majority of glass. It is one of the lightest in weight and can be heavily manipulated. It is most commonly found in windowpanes and bottles.

The impurties found in the raw materials uesd to make glass naturally color glass shades of green, yellow, or blue. Early on, many sands were heavy in iron giving glass a greenish tint. These colors can be removed by adding manganese oxide which makes the glass clear. However, by adding other metal oxides to clear glass beautiful colored glass can be created. Some examples include:
 

• Copper oxides: blue-green

• Gold: red/ruby

• Cobalt: blue

• Manganese oxide: purple

• Iron oxide: shades of green and brown

• Nickel: blue, violet, or black

There are two main types of glass used: Cathedral and Opalescent. 

Cathedral glass is transparent and usually a single color. A normal house window would be considered a clear cathedral. It comes in a wide variety of colors and textures. If you mix two cathedral glass colors together you will get what is called streaky glass.

Opalescent glass is opaque and has a milky apperance. It can be a solid color but is usually a mix of two or more. 

Another type of common glass used is beveled glass. Beveled glass is usually clear and made from thick plate glass. All edges are angeled, or beveled.