pseudoonion

A pseudoonion is a geological formation that can resemble an onion bulb in its layered structure. These formations are not actual plants, but rather rock or mineral deposits that have developed concentric rings over time. The appearance of layering is often due to variations in mineral composition, crystal growth, or the way sediment was deposited and lithified.

The term "pseudoonion" is descriptive, drawing a parallel to the visual characteristics of a true onion. These structures can occur in a variety of geological settings and are typically found in sedimentary rocks or sometimes within mineral veins. The process of their formation usually involves slow, gradual deposition or precipitation of materials.

Identifying a pseudoonion involves examining its internal structure and context within the surrounding rock. Geologists study the composition and arrangement of the layers to understand the environmental conditions under which the formation occurred. While visually striking, pseudoonions do not possess biological functions and are purely mineralogical or geological phenomena. They serve as interesting examples of natural pattern formation within the Earth's crust.