possible tiny fish scale?

[hndmarshall]

this is very tiny almost just a speck found it while digging out a hole in a stone and looking at what was washed out with my microscope camera

[Darktooth]

Look very similar to a gar scale.

[JohnJ]

Looks like a tiny chert flake (not unexpected among the gravels you have been searching).  

[Fossildude19]

I agree with John. 

Although it has a roughly diamond-like  scale shape, I don't see any evidence of ganoid enamel, or true scale morphology. 

[abyssunder]

I agree, also. That is what reminds me of Silex.