Factory defect?

[Sortitallout]

Looks to be a factory defect on a M F Christensen?  3/4”

Thank you

 

[Sortitallout]

Close up

[akroorka]

Image one is classic--we have to see it straight on--from the top.
When one marble hits another (Glass is actually a hard liquid check out old glass windows—it does flow) the result is a “Moon”.
This one I suspect is a “moon” that that “broke out” around the perimeter like an asteroid hitting our Earth’s Moon itself. It was more than likely a direct hit, no glancing or angles involved.
The result is an impact zone that defies my explanation or knowledge. 
The middle stays semi intact, pushing into the glass itself (like a small rise or even to the surface of the original marble). The rest explodes outwards in a semi circle—never to be found again) except by someone’s foot .
Glass is always in motion, if you could place a marble on a stable area and come back 1000 years later it would be flat—or flatter.
Yes I know –pretty deep—no lies here—just glass research.
If you are lucky enough to find a blow out or moon that has the center involved as original—you are lucky—value—well, cool if you think like me.
Marble—On!!
 

[Sortitallout]

Yeah, that’s cool. The science behind it matters. This one is particularly eye catching.

[Alan]

Impact damage.

[Brock]

24 minutes ago, akroorka said:

.
Glass is always in motion, if you could place a marble on a stable area and come back 1000 years later it would be flat—or flatter.
Yes I know –pretty deep—no lies here—just glass research.

 

I have never thought of why it happens before. I have seen old window glass droopy almost melting looking

24 minutes ago, akroorka said:

 

 

[akroorka]

I would call this one an Akro Slag.

Sorry, I got off a bit with my wondering mind.

Marble--On!!

[Sortitallout]

😆