Strontioruizite is an extremely rare strontium-dominant silicate mineral primarily found in hydrothermal vein deposits. It typically forms small, prismatic orange to brown crystals and is of interest primarily to advanced systematic mineral collectors due to its rarity.

Hardness

5-5.5

Mohs

Luster

Vitreous

Streak

Very light brown

Transparency

Transparent

mineralrare

Strontioruizite

Hardness: 5-5.5
Luster: Vitreous
Streak: Very light brown
Transparency: Transparent

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Is this strontioruizite?

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 strontioruizite with a known reference. Strontioruizite sits at Mohs 5-5.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: very light brown.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: orange, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Ruizite

Mohs ~5

How to tell apart: Streak differs, so Strontioruizite leaves very light brown, Ruizite leaves pale apricot.

How to tell apart: Streak differs, so Strontioruizite leaves very light brown, Prehnite leaves white.

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Often found alongside strontioruizite

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

All properties

Chemical formula: Sr₂Mn₂Si₄O₁₁(OH)₄·2H₂O
Mohs hardness: 5-5.5
Density: 3.20 g/cm³
Colors: Orange Brown
Streak: Very light brown
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Prismatic crystals
Cleavage: Good on {010}
Rarity: Rare
Uses: Collector
Host rock: On chemically weathered metamorphosed manganese ore

Where rockhounds find strontioruizite

Classic worldwide localities

N’Chwaning III mine, Kalahari manganese field, Northern Cape province, South Africa

Field-hunting tip

Where it forms: On chemically weathered metamorphosed manganese ore. If you start seeing sugilite, potassic-magnesio-arfvedsonite, lipuite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify strontioruizite?+

Mohs hardness is 5-5.5. Luster: vitreous. The streak is very light brown. Common colors include orange, brown.

Where is strontioruizite found?+

Notable localities include N’Chwaning III mine, Kalahari manganese field, Northern Cape province, South Africa.

What rocks look like strontioruizite?+

Strontioruizite is most often confused with Ruizite, Prehnite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with strontioruizite?+

Strontioruizite commonly co-occurs with Sugilite, Potassic-magnesio-arfvedsonite, Lipuite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does strontioruizite form in?+

Where it forms: On chemically weathered metamorphosed manganese ore. Working float back to the host body is the standard way to chase a fresh occurrence.

What is strontioruizite used for?+

Strontioruizite is used in collector.

Find strontioruizite on the map

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