Akrochordite is a rare manganese magnesium arsenate mineral typically found in metamorphosed manganese deposits. It usually forms as attractive brownish, radial, or granular aggregates and is highly sought after by mineral collectors for its unique crystal structures.
Is this akrochordite?
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 akrochordite with a known reference. Akrochordite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Akrochordite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Akrochordite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: reddish-brown, brown, yellowish-brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: radial aggregates, granular, crusts.
Often confused with
Akrochordite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Synadelphite is the harder of the two (Mohs 4.5 vs. 3.5); streak differs — Akrochordite leaves white, Synadelphite leaves yellowish-brown; luster reads vitreous on Akrochordite and vitreous to greasy on Synadelphite.
Often found alongside akrochordite
Minerals reported to co-occur with akrochordite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg₄Mn₂(AsO₄)(OH)₈·6H₂O
- Mohs hardness
- 3.5
- Density
- 2.7 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Radial Aggregates, Granular, Crusts
- Cleavage
- Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Manganese Ore Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find akrochordite
Classic worldwide localities
- Långban, Sweden
- Sterling Hill, New Jersey, USA
Field-hunting tip
Look in metamorphosed manganese ore deposits country — that is the host setting where akrochordite typically forms. If you start seeing hausmannite, barite, calcite in float, you are in the right ground. Field specimens usually show a radial aggregates, granular, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify akrochordite?+
Where is akrochordite found?+
How much is akrochordite worth?+
Is akrochordite safe to handle?+
What rocks look like akrochordite?+
What minerals are found with akrochordite?+
What kind of rock does akrochordite form in?+
What is akrochordite used for?+
Find akrochordite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
