Nitromagnesite is a highly soluble nitrate mineral that typically forms as efflorescent crusts in arid environments. It is extremely sensitive to humidity and will readily deliquesce or dehydrate, requiring specialized climate-controlled storage for preservation.
Is this nitromagnesite?
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 nitromagnesite with a known reference. Nitromagnesite sits at Mohs 1.5-2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Nitromagnesite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Nitromagnesite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: efflorescent crusts, acicular needles, fibrous masses.
Often confused with
Nitromagnesite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside nitromagnesite
Minerals reported to co-occur with nitromagnesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg(NO₃)₂·6H₂O
- Mohs hardness
- 1.5-2
- Density
- 1.63 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Efflorescent Crusts, Acicular Needles, Fibrous Masses
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Arid Caves, Caliche Deposits, Dry Nitrate-rich Soils
- Typical price
- $20-100 for small study specimens
Where rockhounds find nitromagnesite
Classic worldwide localities
- Chile
- Spain
- Italy
- USA
Field-hunting tip
Look in arid caves, caliche deposits, dry nitrate-rich soils country — that is the host setting where nitromagnesite typically forms. If you start seeing nitronatrite, gypsum, halite in float, you are in the right ground. Field specimens usually show a efflorescent crusts, acicular needles, fibrous masses habit, so train your eye for that shape before scanning the outcrop.



