Hureaulite

Hureaulite is named after its discovery locality, at the Huréaux quarry, St-Sylvestre, 21 km north of Limoges, Haute-Vienne, France.

Hureaulite forms transparent to translucent light rose to pink to rose-violet, orange or yellowish brown long to short prismatic elongated crystals with vitreous to greasy lustre.

Hureaulite gems are usually translucent and moderately included. Therefore faceted stones are very rare. Hureaulite can be used as ornamental material.
General Information
Chemical Formula
Mn
2+
5
(PO
 
4
)
 
2
(PO
 
3
OH)
 
2
· 4H
 
2
O)
Michael O’Donoghue, Gems, Sixth Edition (2006)
Photos of natural/un-cut material from mindat.org
Physical Properties of Hureaulite
Mohs Hardness3.5
Michael O’Donoghue, Gems, Sixth Edition (2006)
Specific Gravity3.19
Michael O’Donoghue, Gems, Sixth Edition (2006)
Optical Properties of Hureaulite
Refractive Index1.647 to 1.667
Michael O’Donoghue, Gems, Sixth Edition (2006) RI for the alpha, beta and gamma rays is 1.647–1.654, 1.654–1.662 and 1.660–1.667
Optical CharacterBiaxial/-
Anthony et al, Handbook of mineralogy (2001)
Birefringence0.012
Michael O’Donoghue, Gems, Sixth Edition (2006)
PleochroismColorless - yellow to pale rose - reddish yellow to reddish brown.
Anthony et al, Handbook of mineralogy (2001)
DispersionVery strong, crossed.
Anthony et al, Handbook of mineralogy (2001)
Colour
Colour (General)Light rose to pink to rose-violet, orange or yellowish brown
Michael O’Donoghue, Gems, Sixth Edition (2006)
TransparencyTransparent,Translucent
Michael O’Donoghue, Gems, Sixth Edition (2006)
LustreGreasy
Michael O’Donoghue, Gems, Sixth Edition (2006)
More from other references
Crystallography of Hureaulite
Crystal SystemMonoclinic
Michael O’Donoghue, Gems, Sixth Edition (2006)
HabitLong to short prismatic elongated crystals
Michael O’Donoghue, Gems, Sixth Edition (2006)
Geological Environment
Where found:Occurs as a late-stage secondary mineral formed by the alteration of primary phosphates in complex granite pegmatites
Michael O’Donoghue, Gems, Sixth Edition (2006)
Further Information
Mineral information:Hureaulite information at mindat.org
Significant Gem Localities
USA
 
  • Connecticut
    • Fairfield Co.
      • Redding (Reading)
        • Branchville
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 418
  • New Hampshire
    • Grafton Co.
      • Groton
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 418
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