Bird feather, positive and negative

This fossil bird feather is from the oligocene age (Stampian, Rupelian) of Cereste in France. 
The piece is preserved in positive/negative condition. The age of this find is about 30 million years.

The stones are reinforced on the back to stabilize them.
The larger slab was broken once, it measures about 8.5 x 7.5 cm, the smaller plate is unbroken, 
it measures about 5.5 x 4.5 cm.

Great piece with nice details, all is original - no manipulations.