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'Hirni' Agate Image Page
'Hirni' Agates, "Hirni-Achate" or "brain-agates", as they are called by a German collector named Rolf Hermanspann, looks like a brain.
Rolf is collecting these agates for more than 10 years now and I was lucky to make a picture from this particular type of agate.
I didn't alter the picture, to make it load faster, because one can see it's features much better now.

This structure is commonly referred to as beekite. It is agate that takes a somewhat different form, something like a coiled rope or concentric but not connected rings.
They are similar in structure to the Conchas from Brazil. Many of the agatized invertebrate fossils become agatized in this fashion. Some of the agates that are called eye agates are of this beekite
structure.