Yowah Nuts are ironstone concretions from Queensland, Australia, that often contain a core of precious opal. When cracked open, they reveal intricate internal patterns of play-of-color, making them highly prized by lapidary artists and mineral collectors.

Hardness

5.5-6.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

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Yowah Nut

Hardness: 5.5-6.5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this yowah nut?

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 yowah nut with a known reference. Yowah Nut sits at Mohs 5.5-6.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Yowah Nut leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Yowah Nut typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: brown, red, green, blue, yellow.
5
Look at form & habit
Crystal system: amorphous. Typical habit: nodular.

Often confused with

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

Often found alongside yowah nut

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

All properties

Chemical formula: SiO₂·nH₂O
Mohs hardness: 5.5-6.5
Density: 1.9-2.3 g/cm³
Colors: Brown Red Green Blue Yellow
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Amorphous
Crystal habit: Nodular
Cleavage: None
Rarity: Uncommon
Uses: Gemstone, Lapidary, Collector
Host rock: Sedimentary Ironstone Concretions
Typical price: $20-300 per specimen

Where rockhounds find yowah nut

Classic worldwide localities

Yowah, Queensland, Australia

Field-hunting tip

Look in sedimentary ironstone concretions country — that is the host setting where yowah nut typically forms. If you start seeing ironstone, quartz, limonite in float, you are in the right ground. Field specimens usually show a nodular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yowah nut?+

Mohs hardness is 5.5-6.5. It typically shows a vitreous luster. The streak is white. Common colors include brown, red, green, blue.

Where is yowah nut found?+

Notable localities include Yowah, Queensland, Australia.

How much is yowah nut worth?+

Typical asking prices fall in the range of $20-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like yowah nut?+

Yowah Nut is most often confused with Boulder Opal. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with yowah nut?+

Yowah Nut commonly co-occurs with ironstone, quartz, limonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does yowah nut form in?+

Yowah Nut typically forms in sedimentary ironstone concretions. Working float back to the host body is the standard way to chase a fresh occurrence.

What is yowah nut used for?+

Yowah Nut is used in gemstone, lapidary, collector.

Find yowah nut on the map

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