Hexaferrum is a rare native iron mineral that crystallizes in the cubic system. It is most famously found as terrestrial occurrences within basaltic rocks on Disko Island in Greenland.

Hardness

Mohs

Luster

Metallic

Streak

Grey

Transparency

Opaque

mineralrare

Hexaferrum

Hexaferrum is a rare native iron mineral that crystallizes in the cubic system. It is most famously found as terrestrial occurrences within basaltic rocks on Disko Island in Greenland.

Hardness: 4
Luster: Metallic
Streak: Grey
Transparency: Opaque

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Is this hexaferrum?

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 hexaferrum with a known reference. Hexaferrum sits at Mohs 4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Hexaferrum leaves a grey streak.
3
Read the luster
Hold the specimen under a strong light. Hexaferrum typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: white, silver-white.
5
Look at form & habit
Crystal system: cubic. Typical habit: grains.

Often confused with

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

mineral

Iron

Mohs 4-5

How to tell apart: Streak differs, so Hexaferrum leaves grey, Iron leaves gray.

How to tell apart: Taenite is the harder of the two (Mohs 5-5.5 vs. 4); streak differs, so Hexaferrum leaves grey, Taenite leaves gray.

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Often found alongside hexaferrum

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

All properties

Chemical formula: Fe
Mohs hardness: 4
Density: 7.9 g/cm³
Colors: White Silver-white
Streak: Grey
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Basalt

Where rockhounds find hexaferrum

Classic worldwide localities

Disko Island, Greenland
North-East Greenland

Field-hunting tip

Look in basalt country, the host setting where hexaferrum typically forms. If you start seeing magnetite, ilmenite, basalt in float, you are in the right ground. Field specimens usually show a grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hexaferrum?+

Mohs hardness is 4. It typically shows a metallic luster. The streak is grey. Common colors include white, silver-white.

Where is hexaferrum found?+

Notable localities include Disko Island, Greenland; North-East Greenland.

What rocks look like hexaferrum?+

Hexaferrum is most often confused with Iron, Taenite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with hexaferrum?+

Hexaferrum commonly co-occurs with Magnetite, Ilmenite, Basalt. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hexaferrum form in?+

Hexaferrum typically forms in basalt. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hexaferrum used for?+

Hexaferrum is used in collector.

Find hexaferrum on the map

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