Rock ID of find in Ramapo Mountains New Jersey

[crumpybumpy]

Any ideas on the ID of this rock found in the Ramapo Mountains of northern New Jersey? Thank you!

 

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[IAMZIM]

It looks to me like a type of metamorphic rock. Maybe someone with better knowledge than I will chime in.

 

[Eu_citzen]

Hornfels? Or a "halleflinta"? (yeah, I don't know the english name)
https://www.britannica.com/science/halleflinta