In my usual daily obsessive compulsive searches across the internet for all things lumia related I came across a NIST publication that lead me down a couple rabbit holes.

Fractography of Ceramic and Glass
https://nvlpubs.nist.gov/nistpubs/sp...p.960-16e2.pdf

This goes a long way towards describing "some" of the more desirable effects that we note when torturing glass for lumia. Quantifying these characteristics I thought would go a long way towards generating a richer dialect for this topic.

I mean, how do you describe the internal structure of bent glass?! How might one purposely load and fracture a material to achieve certain optical properties repeatably and reliably?
This publication helps I believe.

Most interesting, I thought were the generation of wallner Lines via conchoidal fracturing. These introduce some really interesting visuals, especially when they oppose one another and generate these unique dynamic moire interferometry fringes.

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https://en.wikipedia.org/wiki/Conchoidal_fracture

Fun stuff!