As you can see by my offerings here at Origin Minerals, I love concretions. They are funky little pieces of rock art. I like the organic shapes, the soft colors, and the soft stone feel in the hand. Opaline concretions can be found in marls, gypsums and shales. They are sometimes considered a variety of opal but probably impure and really just young Flint nodules which haven’t recrystallized to quartz yet; thus really a rock rather than a mineral.
The white chalky surfaces are not always as pure white as they show up in the pictures, as they are a little hard to photograph. Little works of art, though. Enjoy!
Origin :: Pantano, Camarillas, Agramon, Spain
Dimensions :: 83 x 66 x 20 mm
Weight :: 4.2 oz