Uduminelite is a rare calcium aluminum phosphate. It was approved as a distinct mineral species in 1950, from material found in Japan.

Hardness

3-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

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Uduminelite

Uduminelite is a rare calcium aluminum phosphate. It was approved as a distinct mineral species in 1950, from material found in Japan.

Hardness: 3-4
Luster: Vitreous
Streak: White
Transparency: Translucent

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Is this uduminelite?

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 uduminelite with a known reference. Uduminelite sits at Mohs 3-4, 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: yellow, yellowish-brown.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: fibrous, acicular, or crusts.

Often confused with

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

Often found alongside uduminelite

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

All properties

Chemical formula: Ca₃Al₈(PO₄)₂O₁₂·2H₂O
Mohs hardness: 3-4
Density: 2.7-2.9 g/cm³
Colors: Yellow Yellowish-brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Fibrous, acicular, or crusts
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: kimberlite

Where rockhounds find uduminelite

Classic worldwide localities

Udachnaya Pipe, Yakutia, Russia

Field-hunting tip

Where it forms: kimberlite. If you start seeing calcite, serpentine, phlogopite in float, you are in the right ground. Typical habit: fibrous, acicular, or crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify uduminelite?+

Mohs hardness is 3-4. Luster: vitreous. The streak is white. Common colors include yellow, yellowish-brown.

Where is uduminelite found?+

Notable localities include Udachnaya Pipe, Yakutia, Russia.

What rocks look like uduminelite?+

Uduminelite is most often confused with Aragonite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with uduminelite?+

Uduminelite commonly co-occurs with calcite, serpentine, phlogopite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does uduminelite form in?+

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

What is uduminelite used for?+

Uduminelite is used in collector.

Find uduminelite on the map

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