Sun Violet Bottles

[Tandy]

In response to a post by Big Kitty on Bottle Digging UK, I would like to find out if this idea to explain the violet shades in Sun Violet Bottles is correct. It would seem a reasonable supposition.

Now, here is the idea again:

The colour change is a complex chemical process. We have to assume that glass is either a liquid at all temperatures, or displays characteristics of a liquid. (Probably closer to the truth.)

The manganese dioxide is chemically changed in the manufacture of the glass to a clear compound. By the action of ultra violet, this compound is chemically changed into a violet one, possibly sodium or potassium permanganate "in solution" within the glass.

Can someone with a good chemical background tell all of us if this is correct, or is there another explanation?

 

[IRISH]

Not quite, it's got a lot more to do with UV stabilizing the atomic absorption spectrum of the glass by affecting the electron state of the Manganese Dioxide in the structure of the glass (although it's more "dissolved" in the glass than part of the structure as glass is non-crystalline). Hopefully there are some gemologicaly inclined people here who can explain it better than me [] .

The link below has a bit of info about the absorption spectrum.
http://csep10.phys.utk.edu/astr162/lect/light/absorption.html