What is this rock

[Larrysands]

Images: https://imgur.com/a/sKxzuhK

Basic tests so far/ observations

Small black crystals are seen on the surface of the stone
Is partly magnetic. Holds a magnet to the surface.
Scraped the white/pinkish crystals to get a powder, and used vinegar to test for calcium. Tested side by side with seashell. My rock does not contain calcium carbonate/ limestone.
Sample weighs exactly 20 oz displaces 210ml of water.


Question:

Small black crystals are seen on the surface of the stone

I don't think this could be a meteorite, because of the large crystals on the surface of the stone.
Am i correct in my reasoning?

 

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[Larrysands]

What is this rock?

Found while hiking in Gloucester Massachusetts

Rock is about the size of a human fist.
Weighs 20oz exactly
Displaces 200ml of water
Is magnetic( Holds magnet somewhat)
Scraped the white/pinkish crystals(square) and tested for calcium carbonate. No fizzle so not calcium
Small and large black dots are seen throughout the rock( Picture 2 middle) (Picture 1 bottom right)




My understanding is that a rock can only develop crystals like this during slow cooling while inside of the earth.It looks like the sample underwent some sort of melting. So it must not be a meteorite right?

PS: I don't understand why my post is called Test i would change it if i could

 

[DizzyDigger]

I would agree that it's not a meteorite..looks more like an encrusted
conglomeration of different materials.

Beyond that, I got nuthin'..wish I could be more helpful.

 

[ToddsPoint]

Google porphyry and you will see many examples similar to yours. Gary

 

[Charlie P. (NY)]

Crystals can form in various situations. Salt is a crystalline matrix. Crystals can also be ground down and formed in conglomerates and sedimentary rocks (silica sandstone is silica crystals reformed).

My guess is that you have a chunk of iron-cemented sandstone. (Iron-oxide and silica).