Haüyne is a striking blue sulfate mineral most famous for its vivid, neon-blue color found in the Eifel volcanic region of Germany. It typically forms small dodecahedral crystals within alkaline igneous rocks and is highly prized by collectors for its brilliance and rarity. Collectors should look for sharp, gemmy crystals, though high-quality specimens are often very small.

Hardness

5.5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareSodalite Group family

Haüyne

Hardness: 5.5-6
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this haüyne?

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 haüyne with a known reference. Haüyne sits at Mohs 5.5-6 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Haüyne leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Haüyne typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue, green, yellow, white, colorless.
5
Look at form & habit
Crystal system: isometric. Typical habit: dodecahedral crystals, granular masses.

Often confused with

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

How to tell apart: Streak differs — Haüyne leaves white, Lazurite leaves light blue.

Often found alongside haüyne

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

All properties

Chemical formula: (Na,Ca)₄₋₈Al₆Si₆(O,S)₂₄(SO₄,Cl)₁₋₂
Mohs hardness: 5.5-6
Density: 2.4-2.5 g/cm³
Colors: Blue Green Yellow White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Isometric
Crystal habit: Dodecahedral Crystals, Granular Masses
Cleavage: Dodecahedral
Fluorescence: Orange Under SW UV
Rarity: Rare
Uses: Collector, Gemstone
Host rock: Alkaline Volcanic Rocks, Phonolites
Typical price: $50-500+ per gram depending on size and intensity of color

Where rockhounds find haüyne

Classic worldwide localities

Eifel Mountains, Germany
Monte Somma, Italy
Sar-e-Sang, Afghanistan
Khibiny Massif, Russia

Field-hunting tip

Look in alkaline volcanic rocks, phonolites country — that is the host setting where haüyne typically forms. If you start seeing nepheline, leucite, sanidine in float, you are in the right ground. Field specimens usually show a dodecahedral crystals, granular masses habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify haüyne?+

Mohs hardness is 5.5-6. It typically shows a vitreous luster. The streak is white. Common colors include blue, green, yellow, white.

Where is haüyne found?+

Notable localities include Eifel Mountains, Germany; Monte Somma, Italy; Sar-e-Sang, Afghanistan; Khibiny Massif, Russia.

How much is haüyne worth?+

Typical asking prices fall in the range of $50-500+ per gram depending on size and intensity of color. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like haüyne?+

Haüyne is most often confused with Sodalite, Lazurite, Nosean. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with haüyne?+

Haüyne commonly co-occurs with Nepheline, Leucite, Sanidine, Augite, Apatite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does haüyne form in?+

Haüyne typically forms in alkaline volcanic rocks, phonolites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is haüyne used for?+

Haüyne is used in collector, gemstone.

Find haüyne on the map

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