Group of sub-millimeter grains - please take a look

[CornelDumitru]

Hello!

 

Please take a look at this group of sub-millimeter grains and let me know if they belong with fossils. Micro gastropods ? Eggs ? Sand ?

They are firmly attached inside a superficial fracture of this (presumed hornfels) rock. I brushed the rock with water and soap, washed it in vinegar, polished some parts of it - but the grains are still there. I suspect they are silicified, "glued" to the rock.

All the black grains look kind of the same, including shape; the white grains also show a kinship between them, maybe. The black and the white grains seem to be all related, somehow. All the photos and a few close-up cinematics are in this album:

https://photos.app.goo.gl/XRdjRisg8N4AeXTj7

The precise location where I picked up the rock is shown in the album (Braila county, Romania), could be an alluvial deposit. 

 

 

 

 

 

 

 

 

This camera and the app that I'm using are forcing a strong black/white contrast; with a loupe one can see more gray tones.

Thanks!

 

[Fossildude19]

These look like ostracods, to me.