# Quartz questions



## jonn (Jan 2, 2013)

I wonder if quartz can take more abuse or has a better tolerance to scratching than glassware ? Quartz versus borosilicate? I know that PD, PT, can be calcined or reduced in quartz but what about incineration? Will any jagged parts scratch the quartz? Also, will quartz fracture or crack if it is wetted while hot? :roll: I will do a google and wiki search as well, just wanted to see if the pros had any experiences that I should avoid. Better safe than sorry. Thanks all, Jonn.


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## Lino1406 (Jan 8, 2013)

Certainly hot quartz will break under abrupt cooling


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## Jimmy (Jan 8, 2013)

If you are talking about FUSED quartz, it is very refractory. But anything will crack and break if you throw water on it while it is hot.


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## jonn (Jan 11, 2013)

Thanks guys, yes it is fused quartz I was asking about.


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## lazersteve (Mar 21, 2013)

I can speak from first hand experience that  you can heat a fused quartz dish to red heat and plunge it into cold water with no problems. I have done it. It is very brittle and will break if hit on a hard surface, but it will not fracture from temperature shifts. This fact comes from it's very low thermal expansion coefficient. Compare the thermal expansion coefficient of fused quartz to Pyrex and you will see why fused quartz behaves this way. 

Coefficient of Thermal Expansion

Steve


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## Marcel (Mar 21, 2013)

Lino1406 said:


> Certainly hot quartz will break under abrupt cooling


I got a set of quartz dishes from a company for tryouts and I always cooled the gold button right after melting with some fresh cool water into the dish. I wouldnt have done it if the sales rep. haddn´t told me that it was possible. Never had any dish breaking because of that.


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## bswartzwelder (Mar 21, 2013)

That you can pour water onto a red hot fused quartz dish is unbelievable. I didn't think there was anything that would stand up to that kind of abuse. Verified by no less than two of the best in the business is proof enough to convince me. THANKS for the info. I wiil put that into my ltlle book of notes on recovery/refining.


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## Lou (Mar 21, 2013)

You absolutely can provided that you stay below the temperature at which quartz starts to de-vitrify and re-organize into its other crystal modification...

The quartz inversion:

https://en.wikipedia.org/wiki/Quartz_inversion

Now don't be getting salt, or metal oxides onto it! That will turn it white and hastily shorten its lifespan.

Quartz is great for gold and silver, but it is to be avoided for platinum and palladium due to the formation of brittle intermetallics, platinum silicide and palladium silicide.


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## jonn (Mar 21, 2013)

Thanks for the response folks, steve, you are correct. It can be rapidly quenched with no issues and zone heated as well. Thank you, Lou, thanks for the heads up on Pd and PT silicides, I will look acquaint myself with that. I have a friend who makes jewelry and he welds silver sheets together on a quartz plate I gave him. It works great. We didn't think it would at first due to zone heating and thermal coefficient. But it does :mrgreen:


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