Norsethite is a rare barium magnesium carbonate that often forms distinct rhombohedral crystals similar to dolomite. It is most famously associated with the Green River Formation, where it occurs in oil shales. Collectors should look for its glassy luster and characteristic perfect rhombohedral cleavage to distinguish it from more common carbonate species.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Norsethite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this norsethite?

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 norsethite with a known reference. Norsethite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Norsethite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Norsethite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless, gray.
5
Look at form & habit
Crystal system: trigonal. Typical habit: rhombohedral crystals, massive, granular.

Often confused with

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

Often found alongside norsethite

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

All properties

Chemical formula: BaMg(CO₃)₂
Mohs hardness: 3.5
Density: 3.38 g/cm³
Colors: White Colorless Gray
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Rhombohedral Crystals, Massive, Granular
Cleavage: Perfect On {10-14}
Rarity: Rare
Uses: Collector
Host rock: Evaporitic Sedimentary Sequences, Carbonatites, And Alkaline Igneous Rocks
Typical price: $20-150 per specimen depending on crystal size and clarity

Where rockhounds find norsethite

Classic worldwide localities

Green River Formation, Wyoming, USA
Langban, Sweden
Khibiny Massif, Russia
Magnet Cove, Arkansas, USA

Field-hunting tip

Look in evaporitic sedimentary sequences, carbonatites, and alkaline igneous rocks country — that is the host setting where norsethite typically forms. If you start seeing dolomite, calcite, shortite in float, you are in the right ground. Field specimens usually show a rhombohedral crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify norsethite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless, gray.

Where is norsethite found?+

Notable localities include Green River Formation, Wyoming, USA; Langban, Sweden; Khibiny Massif, Russia; Magnet Cove, Arkansas, USA.

How much is norsethite worth?+

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

What rocks look like norsethite?+

Norsethite is most often confused with Dolomite, Magnesite, Witherite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with norsethite?+

Norsethite commonly co-occurs with Dolomite, Calcite, Shortite, Searlesite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does norsethite form in?+

Norsethite typically forms in evaporitic sedimentary sequences, carbonatites, and alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is norsethite used for?+

Norsethite is used in collector.

Find norsethite on the map

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