Nitratine is a soft, water-soluble nitrate mineral that typically forms as efflorescent crusts or granular masses in extremely arid climates. Due to its high solubility, it is almost exclusively found in hypersaline desert environments like the Atacama Desert, where it remains protected from rainfall.
Is this nitratine?
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 nitratine with a known reference. Nitratine 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, gray, yellowish, brownish.
- 5Look at form & habitCrystal system: trigonal. Typical habit: granular, massive.
Often confused with
Nitratine vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside nitratine
Minerals reported to co-occur with nitratine. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaNO₃
- Mohs hardness
- 1.5-2
- Density
- 2.24-2.29 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Granular, massive
- Cleavage
- Perfect on {1011}; imperfect on {0112}, {0001}
- Rarity
- Rare
- Uses
- Industrial, Fertilizer, Collector
- Host rock
- Principally in bedded deposits formed in playas; in caves, deposited from seeping groundwater leaching nitrates from overlying rocks, especially in very dry and cold climates
Where rockhounds find nitratine
Classic worldwide localities
- Death Valley and along the Armagosa River, Inyo and San Bernardino Cos., California, USA
- Niter Buttes, about 40 km southeast of Lovelock, Churchill Co., Nevada, USA
- Plateau Canyon, 32 km east of Grand Junction, Mesa Co., Colorado, USA
- Organ Mountains, about 12 km east-northeast of Mesquite, Doña Ana Co., in the Jornada del Muerto lava tubes, near Socorro, Socorro Co., New Mexico, USA
- Tarapacá district, along the coast, economically valuable deposits aggregating billions of tons, Chile
- Chuquicamata, Antofagasta, Chile
Field-hunting tip
Where it forms: Principally in bedded deposits formed in playas; in caves, deposited from seeping groundwater leaching nitrates from overlying rocks, especially in very dry and cold climates. If you start seeing niter, nitrocalcite, epsomite in float, you are in the right ground. Typical habit: granular, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nitratine?+
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What rocks look like nitratine?+
What minerals are found with nitratine?+
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Find nitratine on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
