Formula: Be2(BO3)(OH)
Anhydrous borate containing hydroxyl, beryllium-bearing mineral
Specific gravity: 2.347 to 2.372
Hardness: 7½
Streak: White
Colour: Colourless, greyish, yellowish, colourless in transmitted light
Solubility: Soluble in HF


Hambergite is an uncommon accessory mineral in granite and syenite pegmatites. Associated minerals include beryl, danburite, apatite, spodumene, zircon, fluorite, feldspar and quartz (HOM).
Although originally described from an alkaline syenite pegmatite, the majority of hambergite occurrences are in complex lithium-rich granite pegmatites of the elbaite or transitional elbaite-lepidolite subtypes (CM 36.441-446).


In the Czech Republic hambergite occurs as an early phase in massive pegmatites from several localities or more commonly as a late phase in miarolitic pockets. Minerals associated with hambergite include manganese-rich elbaite, albite, quartz, K-feldspar, lepidolite, topaz, beryl, apatite and cookeite. Hambergite formed simultaneously with hydrothermal minerals such as bavenite, herderite and danburite, but prior to zeolites and clay minerals.
The Czech elbaite-bearing pegmatites are characterised by rare occurrence of micas, the presence of manganese-rich elbaite, and dominance of K-feldspar over albite (CM 36.441-446).

At the type locality, Salbutangen, Helgeroa, Langesundsfjorden, Larvik, Vestfold og Telemark, Norway, hambergite occurs in a syenite pegmatite associated with zircon, sodalite, fluorite, ferro-hornblende, feldspar, biotite and analcime (Mindat).

At Stak Nala, Haramosh Mountains, Roundu District, Gilgit-Baltistan, Pakistan, twin crystals of hambergite have been found attached to prisms of tricolored elbaite. Both minerals are partially coated with white fine-grained boron-rich muscovite. This assemblage is consistent with formation in a pocket environment in a granite pegmatite (CM 34.615-621).

At the Little Three Mine, Ramona, Ramona Mining District, San Diego County, California, USA, in the section of the dike in which hambergite was found, cleavelandite was common and formed typical rounded growths between light smoky quartz crystals. The hambergite was found in small nests several inches in diameter, growing on quartz and cleavelandite. Several of the quartz crystals had either implanted or completely embedded hambergite crystals. Aside from quartz the mineral most intimately associated with hambergite is cookeite. Other associated minerals are lepidolite and topaz. These associations point to a genesis for hambergite earlier than the pocket quartz, microcline perthite and topaz, but later than cleavelandite, which was found penetrating hambergite crystals (AM 50.85-95).

Back to Minerals