Apophyllite

Apophyllite is named after Greek “apo” – away and “phyllazein” – to get leaves, alluding to its exfoliation when heated with a blowpipe. They can also be called “fisheye stone”. Apophyllite is popular because of its abundance, color variety, and well-defined crystals, but easy cleavage, brittleness and extreme heat sensitivity make this material difficult to facet

Mineral Photos courtesy of R.Weller/Cochise College