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.
Is this hatertite?
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 hatertite with a known reference. Hatertite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hatertite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Hatertite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-orange.
- 5Look at form & habitCrystal 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
- Colors
- 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.




