Click on a letter above to view the list of gems.  

Hambergite
Current inventory:  1 gem
 

Chemistry:  Be₂(BO₃)(OH,F)

Discovered in 1890;   IMA status: Valid (pre-IMA; Grandfathered).
Hambergite is named after Axel Hamberg (1863 - 1933), a Swedish mineralogist and geographer, who discovered the mineral.

Classification

Mineral Classification:

Borates

Strunz 8th Ed. ID:

5/L.02-10

5 : Nitrates, Carbonates & Borates
L : Shelly borates with [BO2]1- to [B6O10]2-
02 : Hambergite - Rhodizite series

Crystal Data

Crystallography:

Orthorhombic - Dipyramidal

Crystal Habit:

Crystals are typically well-crystallized, prismatic or dipyramidal, with another 20 forms known; striated; to 30 cm

Twinning:

Commonly reticulated; contact twins may be markedly hemimorphic

Physical Properties

Cleavage:

[010] Perfect, [100] Good

Fracture:

Conchoidal to Uneven

Tenacity:

Brittle

Moh's Hardness:

7.5

Density:

2.347 - 2.372 (g/cm³)

Luminescence:

None in most specimens; occassionally weak pink-orange under LW UV

Radioactivity:

Not Radioactive

Optical Properties

Color:

Colorless, Gray white, Yellowish white, White

Transparency:

Transparent to Translucent

Luster:

Vitreous to Dull

Refractive Index:

1.554 - 1.631  Biaxial ( + )

Birefringence:

0.0740

Dispersion:

0.015; Weak; r > v

Pleochroism:

None

Occurances

Geological Setting:

An uncommon accessory mineral in granite pegmatites

Type Locality:

Salbutangen, Helgeroa, Langesundsfjorden, Larvik, Vestfold, Norway

Year Discovered:

1890

View mineral photos:

Hambergite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Hambergite is a very rare and unusual collector's gem. It has remarkable properties - it has the lowest known density of any gem with such high birefringence. Crystals are rarely clean enough for faceting and gems are usually very small. Large, clean gems are a true rarity.

The most notable sources of gem quality Hambergite crystals are Katche village, Molo District, near Momeik, Burma (Myanmar); Anjanabanoana, Madagascar; and the Himalaya Mine, Mesa Grande District, San Diego County, California, USA.
 

  
Hambergite gems for sale: