Hulsite specimens for sale
1 for sale · $200 USD
2 in the gallery
Hulsite is a borate mineral with a complex iron, magnesium, tin and oxygen-silicate composition. It typically forms as modest to well-prismatic crystals that exhibit a brown to bronze-brown color and a resinous to sub-vitreous lustre that highlights its angular faces. Habit can range from short prisms to tabular crystals, often occurring in granular to cobbled aggregates within hydrothermal skarn and igneous rock environments where iron and tin-bearing fluids were active.
- Formula
- (Fe2+,Mg)2(Fe3+,Sn)(BO3)O2
- Rarity
- Rare
- Stability
- Stable
- Collector interest
- Moderate Interest
- Classification notes
- Borate; ludwigite group
Key characteristics
- Crystal system
- orthorhombic
- Mohs hardness
- 6
- Specific gravity
- 4.2–4.3
- Luster
- submetallic
- Transparency
- opaque
- Color
- black, brown
- Streak
- black, brown
- Cleavage
- none
- Fracture
- uneven
- Crystal habit
- prismatic, acicular, granular, massive
Buy Hulsite specimens
View all 1
Where Hulsite is found
Top localities
- Alaska1 specimen
About Hulsite
Notable specimens have been reported from the United States and the Czech Republic, among other localities. In the field, hulsite often accompanies related borates and sulfides within skarn veins and hydrothermal systems, where its presence signals complex geochemical conditions. Collectors appreciate its crystal form, subtle coloration, and the rarity of overtly well-formed crystals relative to more common borates, making good singles or aggregates a desirable addition to a collection.