There's #sapphirine in the Blue Ridge of North Carolina! Ocean crust, crumpled and buried under the high Appalachians and cooked to 800°C and 9 kbar (granulite facies). Olivine & plagioclase reacted to sapphirine/cpx intergrowths (black/white zebra stripes in the image).

This study was done by Aletha Wachter through NSF Research Experience for Undergrads (REU) projects to Ginny Peterson (now #GrandValleyState) & Jeff Ryan(#USF). Lead Helen Lang (#WVU) sadly has passed away too young. #MinCup23