Manganese Biominerals (Todorokite, Romanechite, Birnessite)

Item Description

An unusual American mineral specimen with a scientific story to tell...Chesapeake biominerals, including Hollandite, Todorokite, Romanechite, Birnessite, and other unusual manganese and iron species, form when metal-rich subsurface waters emerge from the face of the cliffs along the western shore of Chesapeake Bay. Microbes exploit the chemical richness of the waters by oxidizing the metals and precipitating minerals in beautifully sculpted masses. The resulting specimens containing mixed amounts of these related species, such as those you see here, are among the finest examples of their style anywhere in the world and are unique in their aesthetic appeal and scientific interest. A portion of all sales of this material goes to support the study of Chesapeake Bay geology through the laboratory of Dr. Robert Hazen.

This specimen is part of the 2024 Dallas Mineral Collecting Symposium benefit auction, donated by Arkenstone, with proceeds benefiting Mineralogical Record, Rocks & Minerals, Tucson Gem and Mineral Society, and mindat.org. Thanks to all of our participants!

Billing for this auction will occur on Monday, August 19th, for payment using PayPal or a credit card. Shipping will be billed at cost.