Stoppaniite is a rare iron-rich member of the beryl group characterized by its distinct blue color. It typically forms as small, transparent prismatic crystals within cavities in evolved granite pegmatites.

Hardness

7.5-8

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareBeryl Group family

Stoppaniite

Hardness: 7.5-8
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this stoppaniite?

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 stoppaniite with a known reference. Stoppaniite sits at Mohs 7.5-8 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Stoppaniite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Stoppaniite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue, light blue, blue-green.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: prismatic crystals.

Often confused with

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

Often found alongside stoppaniite

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

All properties

Chemical formula: Be₃(Fe³⁺,Mg,Fe²⁺)₂Si₆O₁₈·nH₂O
Mohs hardness: 7.5-8
Density: 2.7-2.8 g/cm³
Colors: Blue Light Blue Blue-green
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Prismatic Crystals
Cleavage: Imperfect Basal
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-500 depending on crystal size and quality

Where rockhounds find stoppaniite

Classic worldwide localities

Italy
Madagascar

Field-hunting tip

Look in granite pegmatites country — that is the host setting where stoppaniite typically forms. If you start seeing quartz, k-feldspar, albite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify stoppaniite?+

Mohs hardness is 7.5-8. It typically shows a vitreous luster. The streak is white. Common colors include blue, light blue, blue-green.

Where is stoppaniite found?+

Notable localities include Italy; Madagascar.

How much is stoppaniite worth?+

Typical asking prices fall in the range of $50-500 depending on crystal size and quality. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like stoppaniite?+

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

What minerals are found with stoppaniite?+

Stoppaniite commonly co-occurs with Quartz, K-feldspar, Albite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does stoppaniite form in?+

Stoppaniite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is stoppaniite used for?+

Stoppaniite is used in collector.

Find stoppaniite on the map

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