Depicts a rock fragment containing an ammonite fossil. Following the outline of the fossil, the word "ammonite" is visible. At the top edge, in three consecutive rows, the inscriptions "GEOLOGICAL," "INSTITUTE," and "1869" are placed, while at the bottom, on the left side, the issuance year "2019" is shown, and on the right side, the mint mark "BP" is situated.

Ammonites, marine mollusks of the class Cephalopoda and subclass Ammonoidea, inhabited oceans from the Devonian period, approximately 419 million years ago, until the end of the Cretaceous period, around 66 million years ago. Known for their diverse shapes, sizes, and shell ornamentation, ammonites had coiled shells divided into chambers filled with gas, aiding in buoyancy and depth control. Predatory in nature, they used tentacles to capture prey and a sharp beak to break it down. The name "ammonite" originates from their resemblance to the ram's horns of the ancient Egyptian god Ammon. Valued by scientists, these fossils offer insights into ancient marine environments, evolution, and geological history.

Depicts the building of the Hungarian Mining and Geological Service, formerly the Geological Institute. In the foreground, the pediment adorned with floral motifs; in the background, the peak of the building's roof, with Atlas figures supporting the globe on their shoulders, is visible. At the top edge is the inscription "HUNGARY", below which, in two horizontal rows, the denomination and the text "FORINT" can be read, and at the bottom, integrated into the depiction, the engraver's privy mark is placed.