This is a Jurassic Park replica prop of a mosquito in amber resin, surrounded by rock.
Approx. 5"x3.5" and sits 2.25" off the table at the highest point.

I was given this years ago by a friend in the film industry and was told that it was a cast & crew gift. 
I do not know any more about it.

Description from a similar one found on another site:
(Universal, 1993) Constructed of cast resin with an actual insect embedded in the transparent amber-like center. The area surrounding the central smooth "window" portion is expertly painted to appear as craggy rock.