Amarantite is a rare hydrated iron sulfate typically found as a secondary mineral in the oxidized zones of iron-rich sulfide deposits. Collectors should look for its distinctive deep orange-red tabular crystals often forming subparallel, sheaf-like aggregates.
Is this amarantite?
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 amarantite with a known reference. Amarantite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Amarantite leaves a yellowish-orange streak.
- 3Read the lusterHold the specimen under a strong light. Amarantite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: orange, brownish-red.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, subparallel aggregates, drusy coatings.
Often confused with
Amarantite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Amarantite leaves yellowish-orange, Fibroferrite leaves white; luster reads vitreous on Amarantite and silky on Fibroferrite.
How to tell apart: Streak differs, so Amarantite leaves yellowish-orange, Copiapite leaves yellow; luster reads vitreous on Amarantite and pearly on Copiapite.
How to tell apart: Streak differs, so Amarantite leaves yellowish-orange, Metahohmannite leaves yellow.
Often found alongside amarantite
Minerals reported to co-occur with amarantite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe³⁺₂(SO₄)₂(OH)₂·7H₂O
- Mohs hardness
- 2.5
- Density
- 3.31 g/cm³
- Colors
- Streak
- Yellowish-orange
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Tabular Crystals, Subparallel Aggregates, Drusy Coatings
- Cleavage
- Good On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Sulfide Deposits
- Typical price
- $50-300 per thumbnail or small specimen
Where rockhounds find amarantite
Classic worldwide localities
- Chile (Cerro Pintados)
- Argentina (Capillitas Mine)
- USA (New Almaden district)
Field-hunting tip
Look in oxidized zones of sulfide deposits country, the host setting where amarantite typically forms. If you start seeing fibroferrite, copiapite, hohmannite in float, you are in the right ground. Field specimens usually show a tabular crystals, subparallel aggregates, drusy coatings habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify amarantite?+
Where is amarantite found?+
How much is amarantite worth?+
What rocks look like amarantite?+
What minerals are found with amarantite?+
What kind of rock does amarantite form in?+
What is amarantite used for?+
Find amarantite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
