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The it is more likely to be novaculite type. Looking forward to see it closer after cleaning.

Also try to scratch it with a copper wire. If is scratches it would be more like slate type of stone if not it would go more towards novaculite type i.e.Arkie.
Titanium gray could be just oily...

Let us know what size it is , what true colour after you clean it and also close up picture would help with recognition.