Occurs as euhedral orange grains and as crusts coating beryl in Alpine pegmatites. Usually associated with bavenite. Optically biaxial, faintly pleochroic. Orthorhombic, P2 1 ab, with a = 8.729(5), b = 31.326(11), c = 4.903(2) angstrom, Z = 4. Genesis is related to late fluid activity within the pegmatite.--Modified journal abstract.