Strengite is a relatively rare iron phosphate mineral with the formula: FePO₄ · 2H₂O. The mineral is named after the German mineralogist

Johann August Streng Johann, typically a male given name, is the German form of ''Iohannes'', which is the Latin form of the Greek name ''Iōánnēs'' (), itself derived from Hebrew name '' Yochanan'' () in turn from its extended form (), meaning "Yahweh is Gracious ...

(1830–1897). Lavender, pink or purple in hue, it is similar to

variscite Variscite is a hydrated aluminium phosphate mineral (). It is a relatively rare phosphate mineral. It is sometimes confused with turquoise; however, variscite is usually greener in color. The green color results from the presence of small amounts ...

and is partially soluble, particularly in conditions where there is a low pH and low oxidation-reduction potential.

References

Phosphate minerals Orthorhombic minerals Minerals in space group 61 {{Phosphate-mineral-stub