u/Idlehour_Knives

Ok - I have some context for this rock. It was found in Austin Creek CA and is part of the blueschist metamorphic facies. I am fairly certain it is a amygdaloidal metabasalt that has greenstone portions as well as glaucophane.

What I am unsure of is the mineral assemblage. What is filling the amygdules? Aragonite? Something else? I am also unsure of what is causing the yellow/orange areas.

Took a few microscope shots of a blueschist I collected (with permission) in Cazadero CA recently. Very geologically interesting area - especially if you like subduction zones.

It’s also just a beautiful area. Redwoods, fog, and the Sonoma Coast all make it worth a visit if you’re in the area.