Heidornite is a rare borate-sulfate mineral typically found in marine evaporite sequences. It usually forms small, colorless to white prismatic crystals and is primarily a target for advanced systematic mineral collectors specializing in borate species.
Is this heidornite?
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 heidornite with a known reference. Heidornite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Heidornite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Heidornite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white, yellowish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, sometimes tabular.
Often confused with
Heidornite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside heidornite
Minerals reported to co-occur with heidornite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Ca₃Cl(SO₄)₂B₅O₈(OH)₂
- Mohs hardness
- 4
- Density
- 3.01 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals, Sometimes Tabular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Evaporite Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find heidornite
Classic worldwide localities
- Germany
- United States
Field-hunting tip
Look in evaporite deposits country — that is the host setting where heidornite typically forms. If you start seeing halite, sylvite, anhydrite in float, you are in the right ground. Field specimens usually show a prismatic crystals, sometimes tabular habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify heidornite?+
Where is heidornite found?+
How much is heidornite worth?+
What rocks look like heidornite?+
What minerals are found with heidornite?+
What kind of rock does heidornite form in?+
What is heidornite used for?+
Find heidornite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
