Newberyite in Ancient and Modern Urinary Calculi: Identification and Space Group

Abstract
Relatively large amounts of newberyite, MgHPO4·3H2O, are found in old or very large urinary calculi. Single crystals of struvite, MgNH4 PO46H2O, sometimes show some decomposition to newberyite on aging. The fact that large amounts of struvite are also found in ancient stones implies, however, that special conditions, as yet unknown, are required for decay to occur.