Legrandite is an unusual secondary mineral in the ox oxidized zone of arsenic bearing zinc deposits. Legrandite is rarely found in granite pegmatite. These gemstones are usually translucent to opaque in large sizes. Dice specimens are rare in legrandite. Legrandite is not suitable for wearing with a hardness of 4.5. Legrandite's signature bright yellow will still be in any gem collection.
These gemstones include associated minerals such as adamite, paradamite, köttigite, scorodite, smithsonite, leiteite, renierite, pharmacosiderite, aurichalcite, siderite, goethite and pyrite. Legrandite is reported from Tsumeb, Namibia and is found in Durango, Mexico and the Ojuela Mine, Sterling Hill, New Jersey, USA.