Do Sun Colored Bottles Fade?

[GuntherHess]

Exposure to high levels of heat will reverse the sun’s ultra-violet purpling effects on glass. This procedure is often referred to by collectors as “cookingâ€. During the thermal reversal or “cooking†process, the manganese is once again the key stimulant. In most cases, when a sun “purpled†insulator is heated to high temperatures, generally a step below melting, it will revert back to a shade in close proximity to its original manufactured color. By Reintroducing a "cooked" insulator to direct sunlight the natural purpling process will begin to occur once again, although the resultant color tones may differ from the original. Be aware that deliberate partial exposures can create artificial two-tones as well.

I know you cant do it in a conventional oven. Thats already been tried.
I havent done an experiment in a glass kiln (we do have one here).
Problem is the insulator (or bottle) turns into a puddle if you get it too hot.
Also the cooling cycle can be tricky and the glass often cracks.
I may do an experiment to verify this.

 

[cyberdigger]

Cool! make another one of those candy dishes!! [8D]

 

[cyberdigger]

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[GuntherHess]

make another one of those candy dishes!!

That was my wife's strange experiment.