Manganese Biominerals combo (rare & unusual combination)

Item Description

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 went to support the study of Chesapeake Bay geology through the laboratory of Dr. Robert Hazen (otherwise, collecting was not permitted, and these were part of a group collected for past research uses). 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 are among the finest examples of their species anywhere in the world and are unique in their aesthetic appeal and scientific interest. Dr. Hazen adds "You have most of the best specimens we've collected so far and new ones don't appear all that often. I have written up something (unpublished) on these specimens. We're now proposing that they will be the subject of thesis studies, so formal publications may take a couple of years. But we have done much analytical work to identify species and I can provide a nice technical summary. The age of the specimens is something we want to understand much more fully. On the one hand, they are in Miocene (~15 million year old) sediments and that's the maximum age. On the other hand, the formation mechanism that we are proposing implies that they are much younger, perhaps even forming within the past century. New specimens appear to emerge primarily through the regular erosion of the cliffs, followed by the wave action of the Bay. So our lab will be studying these in the field and in laboratory simulations. This is all very new science, and the importance of understanding the nature of microbial activities is very much a frontier area of mineralogy."