Noelbensonite is a rare barium manganese silicate. It was approved as a distinct mineral species in 1994, from material found at the Woods mine, 30 km north northeast of Tamworth, New South Wales, Australia.

Hardness

Mohs

Luster

Vitreous to greasy

Streak

Yellow brown

Transparency

Translucent

mineralrareHematite Group family

Noelbensonite

Hardness: 4
Luster: Vitreous to greasy
Streak: Yellow brown
Transparency: Translucent

No image

Is this noelbensonite?

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 noelbensonite with a known reference. Noelbensonite 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. Streak: yellow brown.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to greasy.
4
Match the color range
Compare against the expected color range: dark brown.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: blocky, cryptocrystalline, crystalline.

Often confused with

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

mineral

Hausmannite

Mohs 5.5

How to tell apart: Hausmannite is the harder of the two (Mohs 5.5 vs. 4); streak differs, so Noelbensonite leaves yellow brown, Hausmannite leaves dark reddish brown; luster reads vitreous to greasy on Noelbensonite and submetallic on Hausmannite.

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Often found alongside noelbensonite

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

All properties

Chemical formula: BaMn³⁺₂Si₂O₇(OH)₂·H₂O
Mohs hardness: 4
Density: 3.87 g/cm³
Colors: Dark brown
Streak: Yellow brown
Luster: Vitreous to greasy
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Blocky, cryptocrystalline, crystalline
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: As a replacement of NaMn amphibole nemansilite and serandite and as the main or sole constituent of tiny veinlets

Where rockhounds find noelbensonite

Classic worldwide localities

The Woods mine 30 km NNE of Tamworth, New South Wales, Australia (type locality)

Field-hunting tip

Where it forms: As a replacement of NaMn amphibole nemansilite and serandite and as the main or sole constituent of tiny veinlets. If you start seeing hausmannite, braunite, calcite in float, you are in the right ground. Typical habit: blocky, cryptocrystalline, crystalline. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify noelbensonite?+

Mohs hardness is 4. Luster: vitreous to greasy. The streak is yellow brown. Common colors include dark brown.

Where is noelbensonite found?+

Notable localities include The Woods mine 30 km NNE of Tamworth, New South Wales, Australia (type locality).

What rocks look like noelbensonite?+

Noelbensonite is most often confused with Hausmannite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with noelbensonite?+

Noelbensonite commonly co-occurs with Hausmannite, Braunite, Calcite, Hematite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does noelbensonite form in?+

Where it forms: As a replacement of NaMn amphibole nemansilite and serandite and as the main or sole constituent of tiny veinlets. Working float back to the host body is the standard way to chase a fresh occurrence.

What is noelbensonite used for?+

Noelbensonite is used in collector.

Find noelbensonite on the map

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