How is glass made???

[integra818]

I've always been curious as to how glass is made. I know it has something to do with lightning and sand but that's all I know.

[TexasF355F1]

Nothing with lightning, just really really high heat. Not exactly sure how it comes about now-a-days, but vases and really nice glass is hand man.

[Oz]

Made from sand.

[integra818]

Originally Posted by Oz

Made from sand.

...but HOW???

[Steel]

Sand, lime, and something else, all melted together.

Didja know that glass is technically a liquid? Cool, eh?

[integra818]

So if I get some sand and hold a torch to it, will it eventually turn into a liquid-like glass?!?

[Steel]

No, it means that even in its amorphous solid state, it's a liquid, so if you hold a torch to it, it just gets softer and softer, without having an actaul melting "point".

[integra818]

...I'm still lost. Does it get soft enough to turn into a transparrent liquid...like glass???

[replicant_008]

Essentially, glass is made from silica (a form of silicon oxide SI02) with a alkali and in some cases a metal oxide (eg crystal glassware has lead oxide).


White sand is predominantly silica. Heating the sand along with the other powdered ingredients in a calcining furnace for about 5-6 hours stirring frequently produces a material called frit. Frit is then pounded and then vitrified using a furnace. At this point, other materials may be added to give other properties to the final product.

The temperatures required and the time required mean making sand with a blowtorch is possible but in relatively small quantities and quite time consuming. It's also likely the product you get will be of inferior quality.

For those living in volcanic areas, you may have observed obsidian or volcanic glass - Obsidian is the result of volcanic lava coming in contact with water. Often the lava pours into a lake or ocean and is cooled quickly. This process produces a glassy texture in the resulting rock. Iron and magnesium give the obsidian a dark green to black color. It's sometimes mistaken for quartz but because it is an amorphous solid as opposed to the crystalline solid (like quartz) it has similar properties to man-made glass.

Finally, glass is defined as an amorphous solid at room temperature. The chemical makeup of glass precludes the formation of a crystalline or quasi crystalline structure so the application of heat makes it softer without actually reaching a point where it's properties indicate a melting point.

[integra818]

Thanks replicant 008