Florida
When reefs get "fossilized", agatized , parts of it become Baybottom chert which shows the fossils within the stone, similar to coral. Coming from the water and being under water for a long time this material is almost always has a dark patina, often black and brown.
Geologic/chemical process of replacement of the organisms' structures with cryptocrystalline quartz: chalcedony/Agate, even chert. In the case of coral, neat specimens of coral polyps. In baybottom, all kinds of organisms, mainly shell but sometimes there are also a few coral polyps in with the mix of other animals. Both materials will patinate the same to white in sand/dry and in water will take on colors of the river patina. But that frosting patina was almost unique!
photos and information courtesy of tomclark
When reefs get "fossilized", agatized , parts of it become Baybottom chert which shows the fossils within the stone, similar to coral. Coming from the water and being under water for a long time this material is almost always has a dark patina, often black and brown.
Geologic/chemical process of replacement of the organisms' structures with cryptocrystalline quartz: chalcedony/Agate, even chert. In the case of coral, neat specimens of coral polyps. In baybottom, all kinds of organisms, mainly shell but sometimes there are also a few coral polyps in with the mix of other animals. Both materials will patinate the same to white in sand/dry and in water will take on colors of the river patina. But that frosting patina was almost unique!
photos and information courtesy of tomclark
Comment