Variscite

Variscite is a secondary mineral formed by direct deposition from phosphate-bearing water that has reacted with aluminium-rich rocks in a near-surface environment. It was first described in 1837 and named for the locality of Variscia, the historical name of the Vogtland, in Germany. Its appearance often causes it to be confused with turquoise, but variscites color tends to be greener rather than blue. Hardness rating of 4.5 on the Mohs scale.