Hambergite

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Hambergite
Hambergite-rare-09-15a.jpg
2.3 x 1.1 x 1 cm crystal of hambergite on albite from Paprok, Nuristan Province, Afghanistan
General
CategoryBorate mineral
Formula
(repeating unit)
Be2BO3OH
Strunz classification6.AB.05
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPbca
Unit cella = 9.76, b = 12.20
c = 4.43 [Å]; Z = 8
Identification
ColorColorless, pale gray, pale yellow
Crystal habitPrismatic crystals
TwinningOn {110}
CleavagePerfect on {010}, good on {100}
TenacityBrittle
Mohs scale hardness7.5
LusterVitreous
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity2.347–2.372
Optical propertiesBiaxial (+)
Refractive indexnα = 1.554 - 1.560 nβ = 1.587 - 1.591 nγ = 1.628 - 1.631
Birefringenceδ = 0.074
PleochroismColorless
2V angle87°
SolubilitySoluble in HF (Hydrogen fluoride)
References[1][2][3]

Hambergite (Be2BO3OH) is a beryllium borate mineral named after Swedish explorer and mineralogist Axel Hamberg (1863–1933). The mineral occurs as white or colorless orthorhombic crystals.[2][3][1]

Tabular, terminated crystal from the Gem Hill, Mesa Grande District, San Diego County, California (size: 1.5 x .8 x .5 cm)

Occurrence[edit]

Hambergite occurs in beryllium bearing granite pegmatites as a rare accessory phase. It occurs associated with beryl, danburite, apatite, spodumene, zircon, fluorite, feldspar and quartz.[1]

It was first described by mineralogist and geographer W. C. Brøgger in 1890.[4] The type locality is Salbutangen, Helgeroa, Langesundsfjorden, Larvik, Vestfold, Norway where it was found in a pegmatite dike of nepheline syenite composition.[2][5]

References[edit]

  1. ^ a b c "Hambergite" (PDF). Mineral Data Publishing. Retrieved 6 January 2012.
  2. ^ a b c "Hambergite". mindat.org. Retrieved 6 January 2012.
  3. ^ a b "Hambergite Mineral Data". Retrieved 6 January 2012.
  4. ^ Godal, Anne Marit (ed.). "hambergitt". Store norske leksikon (in Norwegian). Norsk nettleksikon. Retrieved 6 January 2012.
  5. ^ Mindat location data

Bibliography[edit]

  • Palache, P.; Berman H.; Frondel, C. (1960). "Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition)" John Wiley and Sons, Inc., New York, pp. 370–372.
  • G. Diego Gatta; Garry J. McIntyre; Geoffrey Bromiley; Alessandro Guastoni; Fabrizio Nestola American Mineralogist (2012) 97 (11-12): 1891–1897. https://doi.org/10.2138/am.2012.4232