Sand "Stromatolite" Desert Onion Concretion 81
Moroccan "Onion" Sand Concretions
Commonly known as "Sand Stromatolites"
Discover the fascinating geometry of Moroccan "Onion" structures. Found in the Saharan desert, these spherical specimens are prized for their concentric, unpolished layers. While often referred to in the trade as "Sand Stromatolites," geologists classify them as pseudo-stromatolites extraordinary barite-cemented sand concretions formed over 500 million years ago.
Whether they originated from ancient microbial mats or purely mineral processes, these "desert onions" remain a striking example of the Earth's natural ability to create complex, symmetrical art during the Cambrian era.
Geological Classification: Pseudo-stromatolite / Barite Concretion.
Origin: Sahara Desert, Morocco.
Age: Pre-Cambrian to Cambrian (approx. 500–540 million years).
Features: Natural, unpolished spherical form with distinct internal "onion-skin" layering
