Kieserite is a common magnesium sulfate mineral found primarily in marine evaporite deposits. It typically occurs as massive, granular, or compact earthy aggregates and is often indistinguishable from other salts without chemical testing or X-ray diffraction.
Is this kieserite?
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 kieserite with a known reference. Kieserite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Kieserite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Kieserite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellowish, grayish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, massive, granular, or encrustations.
Often confused with
Kieserite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Kieserite is noticeably harder (Mohs 3.5 vs. 2-2.5).
How to tell apart: Kieserite is noticeably harder (Mohs 3.5 vs. 2).
How to tell apart: Kieserite is noticeably harder (Mohs 3.5 vs. 2).
Often found alongside kieserite
Minerals reported to co-occur with kieserite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgSO₄·H₂O
- Mohs hardness
- 3.5
- Density
- 2.57 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Massive, Granular, Or Encrustations
- Cleavage
- Distinct in One Direction
- Rarity
- Common
- Uses
- Industrial, Fertilizer, Collector
- Host rock
- Evaporite Deposits
- Typical price
- $10-40 per specimen
Where rockhounds find kieserite
2 mapped spotsClassic worldwide localities
- Stassfurt, Germany
- Carlsbad, New Mexico, USA
- Saskatchewan, Canada
- Soligorsk, Belarus
Field-hunting tip
Look in evaporite deposits country — that is the host setting where kieserite typically forms. If you start seeing halite, sylvite, carnallite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular, or encrustations habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Nevada, Utah — start trip planning there.
Common questions
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Find kieserite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
