"Pale blue, pale green or bluish green globular crusts and individual spheres or hemispheres of minerals in the composition series between turquoise and chalcosiderite are widespread in the Lake Boga granite quarry. They occur most often lining small miarolitic cavities but may also be found on joint planes and in cavities etched in fluorapatite. Individual globules may reach close to 1 mm across. Well formed crystals have not been observed. Massive partial replacements of orthoclase crystals by turquoise have been collected, but are very rare. As an early-formed secondary hydrothermal mineral, turquoise/chalcosiderite is found with most of the other secondary phosphates from Lake Boga. Microprobe analyses of the bluish green crusts show the compositions fall between ferrian turquoise and aluminan chalcosiderite."
Lake Boga granite quarry, Lake Boga, Swan Hill Rural City, Victoria, Australia