5.8" Graveyard Plume Agate Slab - Eastern Oregon

Long known for its beautiful "plume" inclusions that look like moss or snow-covered trees, agate from this area comes from just a couple of small mines. Plumes or dendrites that occur within rock are most often a result of intruding (percolating) mineral solutions that contained manganese and/or iron. These solutions can work their way through microscopic cracks in the rock, leaving behind a branching pattern throughout the agate. To an untrained eye, these can be mistaken for plant fossils within the rock.