Kamotoite-(Y) is a rare hydrated yttrium uranium uranyl carbonate mineral found in oxidized uranium deposits. It typically forms thin, bright yellow platy crystals or coatings and is highly prized by advanced mineral collectors for its complexity and rarity.

Hardness

2-3

Mohs

Luster

Pearly

Streak

Pale Yellow

Transparency

Translucent

mineralrare

Kamotoite-(Y)

Hardness: 2-3
Luster: Pearly
Streak: Pale Yellow
Transparency: Translucent

Is this kamotoite-(y)?

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 kamotoite-(y) with a known reference. Kamotoite-(Y) sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Kamotoite-(Y) leaves a pale yellow streak.
3
Read the luster
Hold the specimen under a strong light. Kamotoite-(Y) typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: yellow, bright yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, tabular aggregates.

Often confused with

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

mineral

Uranophane

Mohs 2.5

How to tell apart: Luster reads pearly on Kamotoite-(Y) and vitreous on Uranophane.

How to tell apart: Kasolite is the harder of the two (Mohs 4-5 vs. 2-3); streak differs — Kamotoite-(Y) leaves pale yellow, Kasolite leaves yellow; luster reads pearly on Kamotoite-(Y) and greasy on Kasolite.

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Often found alongside kamotoite-(y)

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

All properties

Chemical formula: Y₂U₄(UO₂)₄(CO₃)₃O₄(OH)₂·14H₂O
Mohs hardness: 2-3
Density: 4.26 g/cm³
Colors: Yellow Bright Yellow
Streak: Pale Yellow
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Tabular Aggregates
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zone of Uranium-rich Copper-cobalt Deposits
Typical price: $50-500 thumbnail size specimen

Where rockhounds find kamotoite-(y)

Classic worldwide localities

Kamoto-East open-pit mine, Democratic Republic of the Congo

Field-hunting tip

Look in oxidized zone of uranium-rich copper-cobalt deposits country — that is the host setting where kamotoite-(y) typically forms. If you start seeing uraninite, becquerelite, schuilingite-(nd) in float, you are in the right ground. Field specimens usually show a platy crystals, tabular aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kamotoite-(y)?+

Mohs hardness is 2-3. It typically shows a pearly luster. The streak is pale yellow. Common colors include yellow, bright yellow.

Where is kamotoite-(y) found?+

Notable localities include Kamoto-East open-pit mine, Democratic Republic of the Congo.

How much is kamotoite-(y) worth?+

Typical asking prices fall in the range of $50-500 thumbnail size specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is kamotoite-(y) safe to handle?+

This mineral is radioactive. It contains toxic constituents. This mineral is both radioactive and toxic due to its uranium content. Handle with appropriate protective gear and store in a lead-lined container or an isolated environment. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like kamotoite-(y)?+

Kamotoite-(Y) is most often confused with Uranophane, Kasolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with kamotoite-(y)?+

Kamotoite-(Y) commonly co-occurs with Uraninite, Becquerelite, Schuilingite-(Nd). Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kamotoite-(y) form in?+

Kamotoite-(Y) typically forms in oxidized zone of uranium-rich copper-cobalt deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kamotoite-(y) used for?+

Kamotoite-(Y) is used in collector.

Find kamotoite-(y) on the map

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