This copper and quartz mixture is one of the most striking stones I have cut to date. The natural blues and greens are honestly unbeatable! There are so many yummy minerals all jam packed into one juicy slab and the added bonus (as if it needed one) is the void of rare gem silica. Gem silica is the most rare and valuable of all the chalcedony varieties. These pieces are definitely old-stock though we are not 100% on mine of location. We believe either Ray mine or Miami-Inspiration from Arizona as we have had many other pieces in our collection identified from both locations.