Weird effect of Metabisulfite (on Mug)

[tacomaguy20]

Hey guys, I made a 10% metabisufite mix to add to my wine and it said use some warm water so I pulled out one of my mugs and threw some water in the microwave, added the potassium metabisulfite and mixed and then added some cool water. I let it sit in my mug while adding to my wine. Then I cleaned the mug. Now when my mug dries it gets white residue inside and outside of it. It washes or wipes off easily but it comes back. Wondering if anybody knows why this is happening? I wasn't sure if this was the right thread to post but thought someone might know. Pictures attached, it looks kind of cool but I'm guessing I should just toss the mug any ideas?

 

[day_trippr]

That looks like crazing. That glass may have been murdered...

 

[dwhite60]

Crazing. Looks more like a ceramic mug than a glass?

 

[tacomaguy20]

Crazing. Looks more like a ceramic mug than a glass?

Yeah I think it's ceramic. It's weird, I'll wash it and then when it dries, it comes back. I can wipe it off/wash it off and it comes back after it completely dries.. Don't know why or what causes it. I was hoping someone here would know.

 

[Elric]

As @day_tripper mentioned This is crazing.

crazing: Crazing is the phenomenon that produces a network of fine cracks on the surface of a material, for example in a glaze layer. Crazing frequently precedes fracture in some glassy thermoplastic polymers. As it only takes place under tensile stress, the plane of the crazing corresponds to the stress direction. Wikipedia

you aren't getting rid of it when you wash the mug, the moisture just makes it not noticeable. It looks like the glaze was not microwave safe and is now compromised. Your two options are to either live with it like it is or pitch the mug.

cheers

 

[tacomaguy20]

Yeah I tossed it. Thanks for the advice