JonnyRockIt
Tenderfoot
What in the world is this rock? Basalt like but black shiny shards throughout. Found on a beach in Maine. 5”Lx3.5”Wx1.25”D
🔎 UNIDENTIFIED What in the world Rock.
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Neat specimen.
It's what's called a 'porphyry'... an igneous or volcanic rock with a fine-grained matrix and distinct phenocrysts of larger size.. I would say it's likely in the basalt family spectrum, but from the colouration I would guess it's an andesite with phenocrysts of amphibole (hornblende).
Neat specimen.
It's what's called a 'porphyry'... an igneous or volcanic rock with a fine-grained matrix and distinct phenocrysts of larger size.. I would say it's likely in the basalt family spectrum, but from the colouration I would guess it's an andesite with phenocrysts of amphibole (hornblende).
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