Hatertite is an extremely rare sulfate mineral found primarily in the fumarolic environment of volcanic craters. It typically occurs as small, tabular yellow crystals or crusts deposited by volcanic gases.

Hardness
3
Mohs
Luster
Vitreous
Streak
Yellow
Transparency
Translucent

Is this hatertite?

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 hatertite with a known reference. Hatertite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Hatertite leaves a yellow streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Hatertite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: yellow, yellowish-orange.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: tabular crystals, crusts.

Often confused with

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

Often found alongside hatertite

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

All properties

Chemical formula
K₂Na₂(Fe³⁺)₂(SO₄)₄
Mohs hardness
3
Density
3.23 g/cm³
Streak
Yellow
Luster
Vitreous
Transparency
Translucent
Crystal system
Monoclinic
Crystal habit
Tabular Crystals, Crusts
Cleavage
Distinct
Rarity
Rare
Uses
Collector
Host rock
Fumarolic Deposits
Typical price
$50-300 per specimen

Where rockhounds find hatertite

Classic worldwide localities

  • La Fossa crater, Vulcano, Aeolian Islands, Italy

Field-hunting tip

Look in fumarolic deposits country — that is the host setting where hatertite typically forms. If you start seeing thenardite, vanthoffite, euchlorine in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hatertite?+
Mohs hardness is 3. It typically shows a vitreous luster. The streak is yellow. Common colors include yellow, yellowish-orange.
Where is hatertite found?+
Notable localities include La Fossa crater, Vulcano, Aeolian Islands, Italy.
How much is hatertite worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like hatertite?+
Hatertite is most often confused with Vanthoffite, Thenardite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with hatertite?+
Hatertite commonly co-occurs with Thenardite, Vanthoffite, Euchlorine, Hematite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does hatertite form in?+
Hatertite typically forms in fumarolic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is hatertite used for?+
Hatertite is used in collector.

Find hatertite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

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