Danburite in evaporites of the Paradox basin, Utah.

Danburite (CaB ₂ Si ₂ O ₈ ) has been found as nodules in Pennsylvanian age marine evaporites of the Paradox basin, Utah. Originally danburite had been known as a high-temperature mineral that occurs at numerous localities in igneous and metamorphic rocks. Since its discovery in water-insoluble residues from a Louisiana salt dome in 1937, it has been found in several other evaporites. The occurrence of danburite and its relation to the host rock in the Paradox basin evaporites indicates that it most likely formed by diagenetic reaction of boron-rich, high-salinity brines with constituents in the anhydrite host rock.