Hambergite

Hambergite
2.3 × 1.1 × 1 cm crystal of hambergite on albite from Paprok, Nuristan Province, Afghanistan
General
CategoryBorate mineral
FormulaBe2BO3OH
IMA symbolHb
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

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.

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

Occurrence

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.

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

References

  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. 1 2 3 "Hambergite" (PDF). Mineral Data Publishing. Archived from the original (PDF) on 15 July 2012. Retrieved 6 January 2012.
  3. 1 2 3 "Hambergite". mindat.org. Retrieved 6 January 2012.
  4. 1 2 "Hambergite Mineral Data". Retrieved 6 January 2012.
  5. ↑ Godal, Anne Marit (ed.). "hambergitt". Store norske leksikon (in Norwegian). Norsk nettleksikon. Retrieved 6 January 2012.
  6. ↑ Mindat location data

Bibliography