This beautiful interpentetrating twin, fluorite came from the Les Tolonen collection. We were able to acquire 100 flats of his best material, representing his 100 trips to the cave-in-rock district spanning 35 years of his doing business in the area while it was in production. You don't often see complete cubes of fluorite from Illinois (or really any location). Both are zoned with a puplish-blue exterior and a light yellow core in each crystal. The large crystal is sitting on a smaller one that is on a small bit of matrix on the very bottom (if you'd like an acryllic base and mineral tack, just ask and I'll include it). Most Illinois fluorite has damage of one kind or another due to the softness of flluorite and the lack of care during recovery. This piece is in great shape, considering everything. There are a few Tiny chips no bigger than 1 mm, typically along an edge (as pictured). Overall, it's a good twin.