43 Photos
Strengite
Chemical Formula	FePO4 · 2H2O
Species	Phosphates
Crystal System	Orthorhombic
Mohs Scale	3-4
Specific Gravity	2.84
Color	Colorless, pale Purple, deep Purple, red, carmine red, greenish white
Streak	White
Luster	Vitreous
Refractive Index	n = 1.697 - 1.708 n = 1.708 - 1.719 n = 1.741 - 1.745
Diaphaneity	Transparent, Translucent
Cleavage	Distinct/GoodGood on , poor on
Crystal Habit：Botryoidal, radial, spherical
Geological Setting：Secondary mineral formed under surface or near-surface conditions by the alteration of iron-bearing phosphates, such as Triphylite in pegmatite, or Dufrenite, or may occur in limonite ore deposits and gossans, magnetite iron ores, or rarely as a cave mineral.

Strengite is a relatively rare iron phosphate mineral with the formula: FePO₄ · 2H₂O. The mineral is named after the German mineralogist Johann August Streng (1830–1897). Lavender, pink or purple in hue, it is similar to variscite and is partially soluble, particularly in conditions where there is a low pH and low oxidation-reduction potential.