Håleniusite-(La) is an extremely rare lanthanum-dominant fluoride mineral belonging to the fluorite group. It typically occurs as minute octahedral crystals within alkaline pegmatite environments, often requiring micro-analysis for definitive identification.

Hardness

3-4

Mohs

Luster

Earthy

Transparency

Translucent

mineralrareFluorite Group family

Håleniusite-(La)

Hardness: 3-4
Luster: Earthy
Transparency: Translucent

Is this håleniusite-(la)?

4-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 håleniusite-(la) with a known reference. Håleniusite-(La) sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
2
Read the luster
Hold the specimen under a strong light. Luster: earthy.
3
Match the color range
Compare against the expected color range: light yellow.
4
Look at form & habit
Crystal system: cubic. Typical habit: powdery.

Often confused with

Håleniusite-(La) vs. its common look-alikes, and how to tell them apart in the field.

mineral

Fluorite

Mohs 4

How to tell apart: Luster reads earthy on Håleniusite-(La) and vitreous; dull when massive on Fluorite.

Compare →

Often found alongside håleniusite-(la)

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

Quartz
mineral · Mohs 7

All properties

Chemical formula: LaOF
Mohs hardness: 3-4
Density: 6.5 g/cm³
Colors: Light yellow
Luster: Earthy
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Powdery
Rarity: Rare
Uses: Collector
Host rock: Formed by alteration of primary bastnäsite-(La), most likely by a decarbonation reaction

Where rockhounds find håleniusite-(la)

Classic worldwide localities

Bastnäs deposit, Skinnskatteberg District, Västmanland County, Sweden

Field-hunting tip

Where it forms: Formed by alteration of primary bastnäsite-(La), most likely by a decarbonation reaction. If you start seeing ferriallanite-, bastnåsite-, quartz in float, you are in the right ground. Typical habit: powdery. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify håleniusite-(la)?+

Mohs hardness is 3-4. Luster: earthy. Common colors include light yellow.

Where is håleniusite-(la) found?+

Notable localities include Bastnäs deposit, Skinnskatteberg District, Västmanland County, Sweden.

What rocks look like håleniusite-(la)?+

Håleniusite-(La) is most often confused with Fluorite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with håleniusite-(la)?+

Håleniusite-(La) commonly co-occurs with Ferriallanite-, Bastnåsite-, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does håleniusite-(la) form in?+

Where it forms: Formed by alteration of primary bastnäsite-(La), most likely by a decarbonation reaction. Working float back to the host body is the standard way to chase a fresh occurrence.

What is håleniusite-(la) used for?+

Håleniusite-(La) is used in collector.

Find håleniusite-(la) on the map

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