Amber
The image depicts a gnat preserved in amber. A lot of insects have been found to be perfectly maintained in this ancient tree sap.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"Historical Geology/Fossils."
http://en.wikibooks.org/wiki/Historical_Geology/Fossils
Wikibooks
CC BY-SA 3.0.