Aluminomagnesiohulsite is a rare borate mineral belonging to the hulsite group, typically occurring as prismatic crystals within skarn deposits. It is chemically complex, characterized by the substitution of aluminum and magnesium within its structure, and is usually found in association with other borate minerals and magnetite. Collectors prize this species for its rarity and its association with unique metamorphic geologic environments.
Is this aluminomagnesiohulsite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch aluminomagnesiohulsite with a known reference. Aluminomagnesiohulsite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Aluminomagnesiohulsite leaves a brownish black streak.
- 3Read the lusterHold the specimen under a strong light. Aluminomagnesiohulsite typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: black, brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Aluminomagnesiohulsite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Aluminomagnesiohulsite leaves brownish black, Hulsite leaves brownish-black.
How to tell apart: Ludwigite is the harder of the two (Mohs 5 vs. 3.5-4); streak differs — Aluminomagnesiohulsite leaves brownish black, Ludwigite leaves black.
Often found alongside aluminomagnesiohulsite
Minerals reported to co-occur with aluminomagnesiohulsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mg,Fe²⁺)₂(Al,Sn,Mg,Fe³⁺)O₂BO₃
- Mohs hardness
- 3.5-4
- Density
- 3.75 g/cm³
- Streak
- Brownish Black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Skarn
- Typical price
- $50-300 per specimen
Where rockhounds find aluminomagnesiohulsite
Classic worldwide localities
- Tayozhnoye deposit, Siberia, Russia
Field-hunting tip
Look in skarn country — that is the host setting where aluminomagnesiohulsite typically forms. If you start seeing ludwigite, magnetite, forsterite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aluminomagnesiohulsite?+
Where is aluminomagnesiohulsite found?+
How much is aluminomagnesiohulsite worth?+
What rocks look like aluminomagnesiohulsite?+
What minerals are found with aluminomagnesiohulsite?+
What kind of rock does aluminomagnesiohulsite form in?+
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Find aluminomagnesiohulsite on the map
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