Darapskite is a rare hydrous sodium nitrate-sulfate mineral that typically forms in the hyper-arid nitrate fields of the Atacama Desert. Collectors should look for its distinctive tabular crystals or white crusts, often found associated with other rare nitrate minerals in salt flats and evaporite deposits.

Hardness
2.5
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this darapskite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch darapskite with a known reference. Darapskite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Darapskite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Darapskite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: colorless, white, yellowish.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: tabular crystals, granular aggregates, efflorescent crusts.

Often confused with

Darapskite vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside darapskite

Minerals reported to co-occur with darapskite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
Na₃(NO₃)(SO₄)·H₂O
Mohs hardness
2.5
Density
2.2 g/cm³
Streak
White
Luster
Vitreous
Transparency
Transparent
Crystal system
Monoclinic
Crystal habit
Tabular Crystals, Granular Aggregates, Efflorescent Crusts
Cleavage
Perfect On {001}
Rarity
Rare
Uses
Collector
Host rock
Arid Saline Environments and Nitrate Deposits
Typical price
$20-100 thumbnail

Where rockhounds find darapskite

Classic worldwide localities

  • Atacama Desert, Chile
  • Antofagasta, Chile
  • Tarapacá, Chile

Field-hunting tip

Look in arid saline environments and nitrate deposits country — that is the host setting where darapskite typically forms. If you start seeing nitratine, halite, gypsum in float, you are in the right ground. Field specimens usually show a tabular crystals, granular aggregates, efflorescent crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify darapskite?+
Mohs hardness is 2.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, yellowish.
Where is darapskite found?+
Notable localities include Atacama Desert, Chile; Antofagasta, Chile; Tarapacá, Chile.
How much is darapskite worth?+
Typical asking prices fall in the range of $20-100 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like darapskite?+
Darapskite is most often confused with Nitratine, Thenardite, Mirabilite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with darapskite?+
Darapskite commonly co-occurs with Nitratine, Halite, Gypsum, Bloedite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does darapskite form in?+
Darapskite typically forms in arid saline environments and nitrate deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is darapskite used for?+
Darapskite is used in collector.

Find darapskite on the map

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