Dendrites in Amber

November 06, 2020


Photographer: Mila Zinkova
Summary Author: Mila Zinkova; Stu Witmer

Seen above is a microscopic image of a 20 million-year-old Dominican amber. Below the two insects, you can see a plant-looking inclusion in the lower part of the amber. These are dendrites from the Greek word for tree. Common in limestone, dendrites are sometimes called pseudofossils and can be distinguished from fossils by the fractal-like perfection of the branching. They’re actually deposits of hydrous iron or manganese oxides that form when supersaturated solutions of iron or manganese penetrate the limestone and are precipitated on exposure to air at the surface. Other dendritic formations in nature include frost on a window, river basins and in your brain.