Kozoite-(Nd) is an extremely rare rare-earth carbonate mineral typically found as tiny, needle-like acicular crystals or radiating sprays. It is most often discovered in cavities within alkaline pegmatites, where it is frequently associated with minerals like calcite and albite.

Hardness

4-4.5

Mohs

Luster

Vitreous to dull

Transparency

Translucent

mineralrareAncylite Group family

Kozoite-(Nd)

Hardness: 4-4.5
Luster: Vitreous to dull
Transparency: Translucent

No image

Is this kozoite-(nd)?

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 kozoite-(nd) with a known reference. Kozoite-(Nd) sits at Mohs 4-4.5, softer than the next harder reference, harder than the previous one.
2
Read the luster
Hold the specimen under a strong light. Luster: vitreous to dull.
3
Match the color range
Compare against the expected color range: white, pale pinkish purple.
4
Look at form & habit
Crystal system: orthorhombic. Typical habit: microscopic crystals.

Often confused with

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

All properties

Chemical formula: NdCO₃(OH)
Mohs hardness: 4-4.5
Density: 4.77 g/cm³
Colors: WhitePale pinkish purple
Luster: Vitreous to dull
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Microscopic crystals
Rarity: Rare
Uses: Collector, Research
Host rock: By post-magmatic hydrothermal activity in cavities and fissures in alkali olivine basalt

Where rockhounds find kozoite-(nd)

Classic worldwide localities

Niikoba, Hizen-cho, Higashi Matsuura-gun, Saga Prefecture, Japan

Field-hunting tip

Where it forms: By post-magmatic hydrothermal activity in cavities and fissures in alkali olivine basalt. If you start seeing kozoite-, lanthanite-, kimuraite- in float, you are in the right ground. Typical habit: microscopic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kozoite-(nd)?+

Mohs hardness is 4-4.5. Luster: vitreous to dull. Common colors include white, pale pinkish purple.

Where is kozoite-(nd) found?+

Notable localities include Niikoba, Hizen-cho, Higashi Matsuura-gun, Saga Prefecture, Japan.

What rocks look like kozoite-(nd)?+

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

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

Kozoite-(Nd) commonly co-occurs with Kozoite-, Lanthanite-, Kimuraite-. Spotting any of these in float or country rock is a useful trip signal.

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

Where it forms: By post-magmatic hydrothermal activity in cavities and fissures in alkali olivine basalt. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kozoite-(nd) used for?+

Kozoite-(Nd) is used in collector, research.

Find kozoite-(nd) on the map

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