Astrophyllite is highly sought by collectors for its stunning, star-shaped radiating crystal clusters known as stellate habits. It is typically found embedded in igneous rocks like nepheline syenite and exhibits a distinct golden-bronze luster that contrasts beautifully with its matrix.

Hardness

Mohs

Luster

Submetallic

Streak

Golden-brown

Transparency

Translucent

mineraluncommon

Astrophyllite

Hardness: 3
Luster: Submetallic
Streak: Golden-brown
Transparency: Translucent

Is this astrophyllite?

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 astrophyllite with a known reference. Astrophyllite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Astrophyllite leaves a golden-brown streak.
3
Read the luster
Hold the specimen under a strong light. Astrophyllite typically shows a submetallic luster.
4
Match the color range
Compare against the expected color range: bronze, golden-yellow, brown.
5
Look at form & habit
Crystal system: triclinic. Typical habit: bladed, stellate, radiating sprays.

Often confused with

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

mineral

Arfvedsonite

Mohs 5.5-6

How to tell apart: Arfvedsonite is the harder of the two (Mohs 5.5-6 vs. 3); streak differs, so Astrophyllite leaves golden-brown, Arfvedsonite leaves grey to bluish-grey; luster reads submetallic on Astrophyllite and vitreous on Arfvedsonite.

How to tell apart: Aegirine is the harder of the two (Mohs 6 vs. 3); streak differs, so Astrophyllite leaves golden-brown, Aegirine leaves yellowish-grey; luster reads submetallic on Astrophyllite and vitreous on Aegirine.

How to tell apart: Streak differs, so Astrophyllite leaves golden-brown, Biotite leaves white; luster reads submetallic on Astrophyllite and pearly on Biotite.

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Often found alongside astrophyllite

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

All properties

Chemical formula: (K,Na)₃(Fe,Mn)₇Ti₂Si₈O₂₄(O,OH)₇
Mohs hardness: 3
Density: 3.3-3.4 g/cm³
Colors: Bronze Golden-yellow Brown
Streak: Golden-brown
Luster: Submetallic
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Bladed, Stellate, Radiating Sprays
Cleavage: Perfect Micaceous
Rarity: Uncommon
Uses: Collector, Lapidary
Host rock: Alkaline Igneous Rocks, Pegmatites
Typical price: $10-100 for specimens depending on size and star formation quality

Where rockhounds find astrophyllite

Classic worldwide localities

Kola Peninsula, Russia
Langesundsfjord, Norway
El Paso County, Colorado, USA
Mont Saint-Hilaire, Quebec, Canada

Field-hunting tip

Look in alkaline igneous rocks, pegmatites country, the host setting where astrophyllite typically forms. If you start seeing aegirine, nepheline, feldspar in float, you are in the right ground. Field specimens usually show a bladed, stellate, radiating sprays habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify astrophyllite?+

Mohs hardness is 3. It typically shows a submetallic luster. The streak is golden-brown. Common colors include bronze, golden-yellow, brown.

Where is astrophyllite found?+

Notable localities include Kola Peninsula, Russia; Langesundsfjord, Norway; El Paso County, Colorado, USA; Mont Saint-Hilaire, Quebec, Canada.

How much is astrophyllite worth?+

Typical asking prices fall in the range of $10-100 for specimens depending on size and star formation quality. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like astrophyllite?+

Astrophyllite is most often confused with Arfvedsonite, Aegirine, Biotite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with astrophyllite?+

Astrophyllite commonly co-occurs with Aegirine, Nepheline, Feldspar, Zircon. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does astrophyllite form in?+

Astrophyllite typically forms in alkaline igneous rocks, pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is astrophyllite used for?+

Astrophyllite is used in collector, lapidary.

Find astrophyllite on the map

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