Fairly clear piece with an assassin bug. These are in the family Reduviidae; bloodsucking conenose, parasitic on mammals. In 1835 Charles Darwin , in western Argentina was bitten by a similar insect and contracted Chagas' disease. This particular on might be in the genus Empicoris.
Assassin bugs are in the order Hemiptera (true bugs). This order has a variety of families that differ greatly from each other in form. They do however, have common morphological features. All true bugs, for example, have long beaks that are used to suck plant juices or body fluids of insects and even mammal blood.
The piece is about 1.0 x 1.6 x .25 inches in size. There are air bubbles that come in layers. The layer of the assassin bug is clear, allowing good observation of the animal.