Herderite

Big Photo

Brazil
4.07 carats
© Rarestone.com

Herderite is named after Siegmund A.W. von Herder, mining official of Freiberg, Saxony, Germany.

Herderite forms good single crystals, twinning is common. Gem material is transparent and has a range of colours, including yellow, blue, pink, violet and green, some crystals are colourless.

Clear crystals are faceted into attractive gems.

Herderite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
 
 
 

Herderite Gemstones by Size

This table shows distribution of Herderite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.29 cts
Heaviest:5.43 cts
Average:1.72 cts
Total photos:17
Do you have a larger Herderite? Why not upload a photo?
0.29ct to 0.80ct0.80ct to 1.32ct1.32ct to 1.83ct1.83ct to 2.35ct2.35ct to 2.86ct2.86ct to 3.37ct3.37ct to 3.89ct3.89ct to 4.40ct4.40ct to 4.92ct4.92ct to 5.43ct
General Information
Chemical Formula
CaBePO
 
4
(F,OH)
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
More from other references
Photos of natural/un-cut material from mindat.org
Physical Properties of Herderite
Mohs Hardness5 to 5.5
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Specific Gravity2.90 to 3.02
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Cleavage QualityIndistinct
Arthur Thomas, Gemstones (2009)
FractureSub-Conchoidal
Arthur Thomas, Gemstones (2009)
Optical Properties of Herderite
Refractive Index1.587 to 1.642
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Optical CharacterBiaxial/+,-
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Birefringence0.028 to 0.032
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
DispersionNil
Arthur Thomas, Gemstones (2009)
Colour
Colour (General)Greyish blue, colourless, pale green, yellowish.
Walter Schumann, Gemstones of the world (2001)
More from other references
TransparencyTransparent,Translucent
Walter Schumann, Gemstones of the world (2001)
More from other references
LustreVitreous
Walter Schumann, Gemstones of the world (2001)
More from other references
Fluorescence & other light emissions
Fluorescence (General)Commonly greenish to violet
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Fluorescence (Short Wave UV)Some specimens exhibit moderate green fluorescence
Arthur Thomas, Gemstones (2009)
Fluorescence (Long-Wave UV)Some specimens fluoresce deep-blue or moderate green.
Arthur Thomas, Gemstones (2009)
PhosphorescenceSome specimens are reported to have shown persistent phosphorescence
Michael O’Donoghue, Gems, Sixth Edition (2006)
Crystallography of Herderite
Crystal SystemMonoclinic
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
HabitPseudo-orthorhombic crystals
Michael O’Donoghue, Gems, Sixth Edition (2006)
More from other references
Geological Environment
Where found:Is believed to occur in complex granite pegmatites
Michael O’Donoghue, Gems, Sixth Edition (2006)
Further Information
Mineral information:Herderite information at mindat.org
Significant Gem Localities
Myanmar
 
  • Mandalay Region
    • Pyin-Oo-Lwin District
      • Mogok Township
        • Kyauk-Pyat-That
Ted Themelis (2008) Gems & mines of Mogok
    • Yamethin District
Ted Themelis (2008) Gems & mines of Mogok
Copyright © Jolyon & Katya Ralph 1993-2019. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.