Mineral Information and Data:

Struvite
(NH4)MgPO4 • 6H2O [CNMNC approved formula]

Named after Heinrich Christian Gottfried Struve (1722-1851) of the Russian diplomatic service, Consul at Hamburg (Germany).

IMA status : Valid species (Pre-IMA 1845) Grandfathered
CLASSIFICATION 
Dana
(8th edition) :
40.01.01.01  
  (40) Hydrated Phosphates
  (40.01) where A++ B++ (XO4) · x(H2O)
  (40.01.01) Struvite Group
  
Nickel-Strunz
(10th edition) :
08.CH.40
  (08) Phosphates, Arsenates, Vanadates
  (08.C) Phosphates without Additional Anions, with H2O
  (08.CH) With large and medium-sized cations, RO4:H2O < 1:1
  
Crystal system: Orthorhombic System
Point group (H-M): mm2 — pyramidal
Unit cell: a = 6.94Å, b = 11.2Å, c = 6.13Å
Crystal Habit: Crystals short prismatic, thick tabular, equant, coffin-shaped, wedge-shaped, to 2 cm, distinctly hemimorphic
Twinning: On {001} as twin and composition plane, with deep re-entrants.
  
Color: Colorless, becomes white on dehydration
Diaphaneity: Transparent to translucent
Luster: Vitreous, dull when dehydrated
Hardness (Mohs): 2
Measured Density: 1.711 g/cm3
Cleavage: 2; {001} good, {100} poor
Tenacity: Brittle
Fracture: Subconchoidal to uneven
Streak: White
  
Geologic Setting: In peaty earth intermixed with cattle dung (Hamburg, Germany); typically formed in bird or bat guano in caves and surface deposits.
Mineral Association: Newberyite, hannayite, brushite, stercorite
  
Synonyms/varieties: Guanite, Struveite
Other Properties: Piezoelectric. Pyroelectric. H2O Soluble. Gemstone Extremely Rare. BioMineral.
Comments: Slightly dissolves in H2O.
Dehydrates in dry, warm air.

 

Struvite
Struvite scaling
Origin: ?
Sample size 3 x 1.8 x 1 cm
Sample owner: Ray Frost
Photo: Theo Kloprogge

 

Struvite
(zoom-in of above)

 

Struvite
Origin: ?
Sample size: 4 x 3.5 x 2 cm
Sample owner: Ray Frost
Photo: Theo Kloprogge

 

Struvite
(zoom-in of above)

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