Rock that gives off static charge when struck

[michael60622]

Does anyone know the name of a type of rock that gives off a static charge when hit, like struck with a hammer?

 

[technician]

The first thing that comes to mind for me is the piezo-electric effect.
This occurs in some crystals (barium titanate... I think) when they are struck or squeezed a voltage is generated.

 

[phinds]

The first thing that comes to mind for me is the piezo-electric effect.
This occurs in some crystals (barium titanate... I think) when they are struck or squeezed a voltage is generated.

yep, my thought as well. I'm not aware of anything else that could answer this question other than a piezoelectric crystal

 

[D H]

Does anyone know the name of a type of rock that gives off a static charge when hit, like struck with a hammer?

Flint is the prototypical example. Other types of chert will do, as will many other very hard types of rock such as jasper.

 

[phinds]

Flint is the prototypical example. Other types of chert will do, as will many other very hard types of rock such as jasper.

are you talking about a static charge or a spark? Are they the same thing in this case?

 

[Bobbywhy]

Please include quartz crystals! They are piezeoelectric crystals too, and give of cool lights if you hit them together in very dark conditions! There are whole families of P-E materials.

Also see these wiki pages:

http://en.wikipedia.org/wiki/Category:Piezoelectric_materials

http://en.wikipedia.org/wiki/Piezoelectricity

The materials page has fifteen separate kinds of P-E materials, each with its own page.