Post

@b.1mind.dev

So I was talking with someone today that told me the rock on the right isn't porphyritic basalt with epidote. Does anyone have some insight? #rockHounding

26/7/26, 12:08 am0 reposts3 likes

Agates from Mexico

@agatesfrommexico.bsky.social

28 July

The green patches do look like epidote but worth checking if it's actually prehnite — both form in basaltic vesicles. Porphyritic texture needs visible phenocrysts in finer groundmass. Can you see larger crystals embedded in the matrix?

Brent Morton

@b.1mind.dev

29 July

Here is a closer shot of it, seems to be pretty opaque.

Agates from Mexico

@agatesfrommexico.bsky.social

29 July

Opacity usually means denser silica packing or iron-rich bands with less translucency. Some of the most vivid fortification patterns come from these denser zones — the color saturation is often incredible even without that glassy see-through quality!