Norbergite is a member of the humite group typically found in contact-metamorphosed limestone or dolomitic marbles. It is most easily identified in the field by its distinct bright yellow fluorescence under shortwave ultraviolet light.

Hardness

6-6.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareHumite Group family

Norbergite

Hardness: 6-6.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this norbergite?

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 norbergite with a known reference. Norbergite sits at Mohs 6-6.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Norbergite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Norbergite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, orange, brown, colorless.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: granular, massive, or small stubby prismatic crystals.

Often confused with

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

mineral

Chondrodite

Mohs 6-6.5

How to tell apart: Luster reads vitreous on Norbergite and vitreous to resinous on Chondrodite.

Often found alongside norbergite

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

All properties

Chemical formula: Mg₃(SiO₄)(F,OH)₂
Mohs hardness: 6-6.5
Density: 3.15-3.20 g/cm³
Colors: Yellow Orange Brown Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Granular, Massive, Or Small Stubby Prismatic Crystals
Cleavage: Poor in One Direction
Fluorescence: Bright Yellow Under SW UV
Rarity: Rare
Uses: Collector
Host rock: Metamorphosed Limestones and Marbles
Typical price: $20-150 for specimens depending on size and quality

Where rockhounds find norbergite

Classic worldwide localities

Norberg, Sweden
Franklin, New Jersey, USA
Amity, New York, USA
Sahara Desert, Algeria

Field-hunting tip

Look in metamorphosed limestones and marbles country — that is the host setting where norbergite typically forms. If you start seeing calcite, dolomite, phlogopite in float, you are in the right ground. Field specimens usually show a granular, massive, or small stubby prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify norbergite?+

Mohs hardness is 6-6.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, orange, brown, colorless.

Where is norbergite found?+

Notable localities include Norberg, Sweden; Franklin, New Jersey, USA; Amity, New York, USA; Sahara Desert, Algeria.

How much is norbergite worth?+

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

What rocks look like norbergite?+

Norbergite is most often confused with Chondrodite, Humite, Clinohumite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with norbergite?+

Norbergite commonly co-occurs with Calcite, Dolomite, Phlogopite, Tremolite, Diopside. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does norbergite form in?+

Norbergite typically forms in metamorphosed limestones and marbles. Working float back to the host body is the standard way to chase a fresh occurrence.

What is norbergite used for?+

Norbergite is used in collector.

Find norbergite on the map

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