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, 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.