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

mineralrare

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. Uduminelite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Uduminelite typically shows a vitreous luster.
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

Look in kimberlite country, the host setting where uduminelite typically forms. If you start seeing calcite, serpentine, phlogopite in float, you are in the right ground. Field specimens usually show a fibrous, acicular, or crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify uduminelite?+

Mohs hardness is 3-4. It typically shows a vitreous luster. 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?+

Uduminelite typically forms in 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.