Aluminosugilite is a rare member of the Sugilite group where aluminum replaces iron or manganese in the crystal structure. It typically appears as massive, translucent material and is highly sought after by collectors for its vibrant purple to pink hues. It is primarily found in the manganese-rich environments of the Kalahari Manganese Fields.

Hardness

6-6.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareSugilite family

Aluminosugilite

Hardness: 6-6.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this aluminosugilite?

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 aluminosugilite with a known reference. Aluminosugilite sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: pink, violet, reddish-purple.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: massive.

Often confused with

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

How to tell apart: Aluminosugilite is noticeably harder (Mohs 6-6.5 vs. 2.5-4); luster reads vitreous on Aluminosugilite and pearly to vitreous on Lepidolite.

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Often found alongside aluminosugilite

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

All properties

Chemical formula: KNa₂Al₂Li₃Si₁₂O₃₀
Mohs hardness: 6-6.5
Density: 2.7-2.8 g/cm³
Colors: Pink VioletReddish-purple
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Massive
Cleavage: Indistinct, poor on (0001)
Rarity: Rare
Uses: Collector, Lapidary
Host rock: metasomatized manganese deposits

Where rockhounds find aluminosugilite

Classic worldwide localities

Wessels Mine, South Africa
Kalahari Manganese Fields, South Africa

Field-hunting tip

Where it forms: metasomatized manganese deposits. If you start seeing pectolite, aegirine, bustamite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify aluminosugilite?+

Mohs hardness is 6-6.5. Luster: vitreous. The streak is white. Common colors include pink, violet, reddish-purple.

Where is aluminosugilite found?+

Notable localities include Wessels Mine, South Africa; Kalahari Manganese Fields, South Africa.

What rocks look like aluminosugilite?+

Aluminosugilite is most often confused with Sugilite, Charoite, Lepidolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with aluminosugilite?+

Aluminosugilite commonly co-occurs with Pectolite, Aegirine, Bustamite, Richterite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does aluminosugilite form in?+

Where it forms: metasomatized manganese deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is aluminosugilite used for?+

Aluminosugilite is used in collector, lapidary.

Find aluminosugilite on the map

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