(Mg,Fe)Al₂(PO₄)₄(OH)

This sample of lazulite is displayed in the Smithsonian Museum of Natural History. Lazulite is a phosphate mineral of aluminum, magnesium and iron with the composition (Mg,Fe)Al₂(PO₄)₄(OH). The sample at left is about 10 cm across and is from Rapid Creek, Yukon Territory, Canada. This sample is described as lazulite with quartz and siderite.