https://en.wikipedia.org/wiki/Rehbinder_effect
can be leveraged to cut glass and make flint easier to chip off (Indigenous peoples used a variation of this to create arrowheads - source?)
https://en.wikipedia.org/wiki/Rehbinder_effect
can be leveraged to cut glass and make flint easier to chip off (Indigenous peoples used a variation of this to create arrowheads - source?)