Possible petrified oyster shell?

[Glitterhorse]

Hello! I found this item in the mouth of a creek that empties into The Great South Bay on L.I. The creek has been used by Indigenous Peoples before European settlers arrived circa 1720. 
 

Is this a petrified oyster? I can’t tell for sure, but I feel the dark/gray/silver area is what’s left of the calcium? Any help would be greatly appreciated! 

[Tidgy's Dad]

I think it's just a weirdly shaped piece of chert. 

[Glitterhorse]

4 minutes ago, Tidgy's Dad said:

I think it's just a weirdly shaped piece of chert. 

That’s a good first observation, thank you. The shape and some of the features (and in more than one place) match too closely to a bivalve for me to dismiss the piece so fast.

 

Why do you feel it’s just a weird piece of chert? I posted here to learn so I’d appreciate more information, please. 

[Tidgy's Dad]

The first couple of pictures show a shape that could be interpreted through pareidolia as being suggestive of an irregularly shaped bivalve such as an oyster. 

It may even be an oyster covered in chert, but I don't think so, the other side is clearly just geological and I'm pretty sure it is just chert or/ and other minerals. 

I guess it's just experience from seeing tens of thousands of chert pieces that resemble other things. 

They've led me up the garden path on many occasions. 

Let's see what other folks say. 

I am not always right. 

[Glitterhorse]

Thank you. I’d rather know the truth than think it’s something other than a rock formation. Either way, I enjoyed the trip and there’s some wampum and a fishing net weight that came from this area, so it’s been fun. 

 

Edited October 9, 2023 by Glitterhorse