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Glass Identification - Post here for all ID requests => Glass => Topic started by: chopin-liszt on October 22, 2017, 12:49:05 PM

Title: Chemistry of crystal versus soda glass interaction with silver to create yellow;
Post by: chopin-liszt on October 22, 2017, 12:49:05 PM

It has long been a mystery to me why the shades of yellows produced at Mdina in the ranges Tiger/Marble and the yellow edges of Crystal Blue Stripe changed from being a deep egg-yolk colour to a much paler ivory shade.
I don't think it's nearly so attractive.
But the other evening I had a thought.
Around '86, they started using crystal rather than the rather poor quality of soda sort of cullet they had been able to get previously.

Could it be that the change in the basic metal chemistry is responsible for the different colour, from egg-yolk to ivory?
This is an example of the later pale ivory, a Marble globe.

Title: Re: Chemistry of crystal versus soda glass interaction with silver to create yellow;
Post by: chopin-liszt on October 22, 2017, 02:34:38 PM

And this is a nice example of earlier Tiger, with the much deeper shade of yellow.

Title: Re: Chemistry of crystal versus soda glass interaction with silver to create yellow;
Post by: Lustrousstone on October 22, 2017, 02:44:33 PM

It might be the change from silver chloride to silver nitrate.

Title: Re: Chemistry of crystal versus soda glass interaction with silver to create yellow;
Post by: chopin-liszt on October 22, 2017, 02:59:41 PM

I had wondered if they did that.
Do we actually know if they changed from using the chloride to the nitrate when making yellows and greens and using that with blues, instead of the reds it was originally used with, for making browns?
Is that something that's now common knowledge, somewhere else?

Is silver nitrate cheaper than silver chloride? I never encountered the chloride, but I did use silver nitrate in labs. It burned holes in everything.  ;D