Achyrophanite is a historical term for a variety of iron-rich garnet, often associated with the almandine-spessartine series. It typically forms as granular or poorly defined dodecahedral crystals in metamorphic environments and is primarily sought by systematic mineral collectors.

Hardness

6.5-7.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareGarnet Group family

Achyrophanite

Hardness: 6.5-7.5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this achyrophanite?

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 achyrophanite with a known reference. Achyrophanite sits at Mohs 6.5-7.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Achyrophanite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Achyrophanite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: dark brown, brownish-red.
5
Look at form & habit
Crystal system: cubic. Typical habit: dodecahedral crystals.

Often confused with

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

Often found alongside achyrophanite

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

All properties

Chemical formula: (Fe,Mg,Mn)₃Al₂(SiO₄)₃
Mohs hardness: 6.5-7.5
Density: 3.8-4.1 g/cm³
Colors: Dark Brown Brownish-red
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Dodecahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Metamorphic Rocks
Typical price: $20-150 per specimen

Where rockhounds find achyrophanite

Classic worldwide localities

Norway
Sweden
Czech Republic

Field-hunting tip

Look in metamorphic rocks country — that is the host setting where achyrophanite typically forms. If you start seeing quartz, biotite, feldspar in float, you are in the right ground. Field specimens usually show a dodecahedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify achyrophanite?+

Mohs hardness is 6.5-7.5. It typically shows a vitreous luster. The streak is white. Common colors include dark brown, brownish-red.

Where is achyrophanite found?+

Notable localities include Norway; Sweden; Czech Republic.

How much is achyrophanite worth?+

Typical asking prices fall in the range of $20-150 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like achyrophanite?+

Achyrophanite is most often confused with Almandite, Spessartine, Andradite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with achyrophanite?+

Achyrophanite commonly co-occurs with Quartz, Biotite, Feldspar. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does achyrophanite form in?+

Achyrophanite typically forms in metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is achyrophanite used for?+

Achyrophanite is used in collector.

Find achyrophanite on the map

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