Bischofite is a highly deliquescent mineral that forms in evaporite deposits, meaning it will dissolve in moist air or even liquefy if handled with damp fingers. Collectors must store this mineral in an airtight, low-humidity environment to prevent it from breaking down. It is typically found in massive or granular forms within salt beds.
Is this bischofite?
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 bischofite with a known reference. Bischofite sits at Mohs 1-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to dull.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: deliquescent, fibrous, massive.
Often confused with
Bischofite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside bischofite
Minerals reported to co-occur with bischofite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgCl₂·6H₂O
- Mohs hardness
- 1-2
- Density
- 1.591-1.604 g/cm³
- Streak
- White
- Luster
- Vitreous to dull
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Deliquescent, fibrous, massive
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector, Scientific research
- Host rock
- In saline deposits; probably in part secondary, formed from carnallite
Where rockhounds find bischofite
1 mapped spotsClassic worldwide localities
- Stassfurt-Leopoldshall, 34 km south of Magdeburg, Saxony-Anhalt, Germany
- Vienenburg and Aschersleben, Lower Saxony, Germany
- Lake Inder, Kazakhstan
Field-hunting tip
Where it forms: In saline deposits; probably in part secondary, formed from carnallite. If you start seeing carnallite, halite, kieserite in float, you are in the right ground. Typical habit: deliquescent, fibrous, massive. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Nevada. Start trip planning there.
Common questions
How do you identify bischofite?+
Where is bischofite found?+
Can I find bischofite in the United States?+
What rocks look like bischofite?+
What minerals are found with bischofite?+
What kind of rock does bischofite form in?+
What is bischofite used for?+
Find bischofite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
