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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 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
- 1.46-1.58 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Efflorescent crusts, acicular needles, fibrous masses
- Cleavage
- Perfect on {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare cave deposit in humidities up to 78%, typically formed as a leachate of bat guano; may be a component of mixed salts
Where rockhounds find nitromagnesite
Classic worldwide localities
- Nicojack Cave, Madison Co., Kentucky, and in a cave near Corydon, Harrison Co., Indiana, USA
- Independence Cave, Botswana
- Arnhem, Gâuab, Elephant, Uisib I, and Kimberlite Caves, Namibia
- Pulo di Molfetta caves, Apulia, Italy
Field-hunting tip
Where it forms: A rare cave deposit in humidities up to 78%, typically formed as a leachate of bat guano; may be a component of mixed salts. If you start seeing nitrocalcite in float, you are in the right ground. Typical habit: efflorescent crusts, acicular needles, fibrous masses. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nitromagnesite?+
Where is nitromagnesite found?+
What rocks look like nitromagnesite?+
What minerals are found with nitromagnesite?+
What kind of rock does nitromagnesite form in?+
What is nitromagnesite used for?+
Find nitromagnesite on the map
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