Hohmannite is a rare, vibrant orange iron sulfate mineral that forms as a secondary product in the oxidation zones of sulfide ore deposits. It is most commonly found as microscopic tabular crystals or granular crusts, often associated with other rare sulfates in arid mining regions. Due to its solubility and sensitivity to hydration, specimens should be stored in a cool, dry environment to maintain their stability.
Is this hohmannite?
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 hohmannite with a known reference. Hohmannite 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. Hohmannite leaves a yellowish orange streak.
- 3Read the lusterHold the specimen under a strong light. Hohmannite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: orange, brownish orange, reddish orange.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, massive, granular, encrustations.
Often confused with
Hohmannite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Hohmannite leaves yellowish orange, Amarantite leaves yellowish-orange.
How to tell apart: Streak differs — Hohmannite leaves yellowish orange, Metavoltine leaves yellow.
How to tell apart: Streak differs — Hohmannite leaves yellowish orange, Copiapite leaves yellow; luster reads vitreous on Hohmannite and pearly on Copiapite.
Often found alongside hohmannite
Minerals reported to co-occur with hohmannite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₂³⁺(SO₄)₂O·8H₂O
- Mohs hardness
- 3
- Density
- 2.44 g/cm³
- Streak
- Yellowish Orange
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Tabular Crystals, Massive, Granular, Encrustations
- Cleavage
- Distinct On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Sulfide Ore Deposits
- Typical price
- $20-150 for micro to thumbnail specimens
Where rockhounds find hohmannite
Classic worldwide localities
- Chuquicamata, Chile
- Cerro Pintados, Chile
- Alcaparrosa Mine, Chile
- Rio Tinto, Spain
Field-hunting tip
Look in oxidized zones of sulfide ore deposits country — that is the host setting where hohmannite typically forms. If you start seeing amarantite, copiapite, fibroferrite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular, encrustations habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hohmannite?+
Where is hohmannite found?+
How much is hohmannite worth?+
What rocks look like hohmannite?+
What minerals are found with hohmannite?+
What kind of rock does hohmannite form in?+
What is hohmannite used for?+
Find hohmannite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
