Kozoite-(La) is an extremely rare rare-earth carbonate mineral typically found as small, delicate acicular crystals or radiating fans. It was first described from Japan and is highly prized by systematic mineral collectors for its complexity and scarcity in the alkalic rock environments where it forms.

Hardness

4-4.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareAncylite Group family

Kozoite-(La)

Hardness: 4-4.5
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this kozoite-(la)?

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 kozoite-(la) with a known reference. Kozoite-(La) sits at Mohs 4-4.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Kozoite-(La) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Kozoite-(La) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless, pale pink.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: acicular or prismatic crystals, radiating aggregates.

Often confused with

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

Often found alongside kozoite-(la)

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

All properties

Chemical formula: (La,Nd,Ca,Sr)₂(CO₃)₃(OH,F)₂
Mohs hardness: 4-4.5
Density: 4.26 g/cm³
Colors: White Colorless Pale Pink
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Acicular or Prismatic Crystals, Radiating Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Alkalic Igneous Rocks, Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find kozoite-(la)

Classic worldwide localities

Tsushima Island, Japan
Mont Saint-Hilaire, Canada

Field-hunting tip

Look in alkalic igneous rocks, hydrothermal veins country — that is the host setting where kozoite-(la) typically forms. If you start seeing calcite, quartz, chlorite in float, you are in the right ground. Field specimens usually show a acicular or prismatic crystals, radiating aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kozoite-(la)?+

Mohs hardness is 4-4.5. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless, pale pink.

Where is kozoite-(la) found?+

Notable localities include Tsushima Island, Japan; Mont Saint-Hilaire, Canada.

How much is kozoite-(la) worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like kozoite-(la)?+

Kozoite-(La) is most often confused with Ancylite-(Ce), Kozoite-(Nd). A quick hardness test and a streak check separate the look-alikes faster than color alone.

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

Kozoite-(La) commonly co-occurs with Calcite, Quartz, Chlorite, Fluorite. Spotting any of these in float or country rock is a useful trip signal.

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

Kozoite-(La) typically forms in alkalic igneous rocks, hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kozoite-(la) used for?+

Kozoite-(La) is used in collector.

Find kozoite-(la) on the map

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