$100Median
3Sold (12 mo)
$450Last sale
Bertrandite specimens for sale
8 for sale · $300–$8,500 USD
63 in the gallery
Bertrandite is a beryllium silicate mineral that forms in pegmatites and hydrothermal veins, typically presenting as colorless to yellow crystals with a transparent to translucent appearance and a vitreous to adamantine luster. Crystals are often prismatic and may occur in aggregates or layered masses, sometimes granting a delicate, columnar impression. Notable localities include districts in the United States and Kazakhstan where well-formed specimens have been collected, as well as occurrences in Brazil, Austria, and China that contribute to its diverse crystallographic styles.
- Formula
- Be4(Si2O7)(OH)2
- Rarity
- Common
- Stability
- Stable
- Collector interest
- Moderate Interest
- Classification notes
- Sorosilicate, Strunz 9.BD.05
Key characteristics
- Crystal system
- orthorhombic
- Mohs hardness
- 6–7
- Specific gravity
- 2.57–2.6
- Luster
- vitreous, pearly
- Transparency
- transparent, translucent
- Color
- colorless, white, yellow
- Streak
- white
- Cleavage
- perfect
- Fracture
- uneven, conchoidal
- Crystal habit
- tabular, prismatic, radiating, massive, granular
Buy Bertrandite specimens
View all 8Where Bertrandite is found
Top localities
- Golconda pegmatite field14 specimens
- Akchatau Mine9 specimens
- Mt Antero5 specimens
- Papachacra4 specimens
- Lohning quarry2 specimens
- Yaogangxian Mine2 specimens
- Governador Valadares2 specimens
- Furka basis tunnel1 specimen
- Lake George1 specimen
- Rio Grande do Norte1 specimen
About Bertrandite
Collectors prize Bertrandite for its associations with beryl-bearing assemblages and the quality of its crystal faces, which can be sharp and well developed. Its relation to beryllium-bearing mineral suites, and the presence of associated minerals such as phenakite and tourmaline in some localities, add to its geologic interest. The mineral’s relatively rare occurrence and crisp habit in suitable locales make clean, undamaged crystals particularly desirable for careful display and study.
