Strengite

Strengite
A small crystal of Strengite
General
CategoryMineral
Formula
(repeating unit)
FePO4·2H2O
IMA symbolStg[1]
Strunz classification8.CD.10
Dana classification40.04.01.02
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M Symbol: (2/m 2/m 2/m)
Space groupPcab
Identification
Formula mass186.85 g/mol
ColorColorless, pale violet, deep violet, red, carmine red, greenish white
Crystal habitBotryoidal, radial, spherical
Cleavage{010} Good, {001} Poor
Mohs scale hardness3.5–4
LusterVitreous
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity2.84
Density2.87 g/cm3
Optical propertiesBiaxial (+)
2V angle72° – 88°
Dispersionr < v, relatively strong
References[2][3][4]

Strengite is a relatively rare iron phosphate mineral with the formula: FePO4·2H2O.[5] The mineral is named after the German mineralogist Johann August Streng [de] (1830–1897).[6] Lavender, pink or purple in hue, it is similar to variscite[7] and is partially soluble, particularly in conditions where there is a low pH and low oxidation-reduction potential.[5] The color comes from ferric ion (Fe3+).[8]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ "Strengite Mineral Data". Webmineral.com. Retrieved 2011-10-25.
  3. ^ "Strengite mineral information and data". Mindat.org. Retrieved 2011-10-25.
  4. ^ "STRENGITE (Hydrated Iron Phosphate)". Retrieved 2011-10-25.
  5. ^ a b Cite error: The named reference science179_4073_564 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference senning2007 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference pough_peterson1997 was invoked but never defined (see the help page).
  8. ^ "Minerals Colored by Metal Ions". minerals.gps.caltech.edu. Retrieved 2023-03-01.