This piece is super cool. Many mineral collectors love specimens that tell a story, and this one definitely does while looking good too! The balls grow radially and if you look to the top two balls you can see where a shell layer has been ruptured displaying the portion beneath. The corona surrounding the balls make a very aesthetic picture but give a glimpse at the formation of this find. Originally, each ball would have been completely surrounded by this corona zone. Looking at this specimen you can see how the corona has been preferentially dissolved, and when you rotate the specimen you get an amazing cross-section of this phenomenon! Plus you can see the relationship between the Chalcopyrite and the mudstone matrix, the complex lumpiness of matrix is super intriguing. This piece is both visually and intellectually stimulating Read up on the scientific analysis of these at https://bit.ly/2MPR6Fi