Variscite

(Utahlite)
Chemistry: Hydrous aluminum iron phosphate; amarice with quartz.
Crystal system: Orthorhombic; massive as nodules, cavity fillers and crusts.
Color: Semi translucent to opaque; yellow green, bluish green, greenish blue; specimens contain brownish yellow to greenish yellow matrix.
Hardness: 5
Cleavage: Perfect: 1 direction; Fracture: brittle, conchoidal.
Specific gravity: 2.55 (2.52- 2.6)
Refractive index: 1.56 mean (1.56-1.59); biaxial negative.
Luster: Massive: vitreous, dull.
Dispersion:-
Dichroism: -
Occurrence: Sedimentary (by direct deposition from phosphate-bearing water that has reacted with aluminum rich rocks in near surface environments); Australia, USA.

Notes
Sometimes called Utahlite from its USA occurrence; may look like turquoise but hardness and SG lower; spectrum: strong line at 688nm, weak line at 650nm, not diagnostic; cabochons, carvings.