Pilawite-(Y) is an exceptionally rare silicate mineral member of the gadolinite group, typically found in pegmatitic environments. Collectors should look for dark, heavy crystals often displaying metamict features due to natural radioactive decay.

Hardness

6.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Opaque

mineralrareGadolinite Group family

Pilawite-(Y)

Hardness: 6.5-7
Luster: Vitreous
Streak: White
Transparency: Opaque

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Is this pilawite-(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 pilawite-(y) with a known reference. Pilawite-(Y) sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Pilawite-(Y) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Pilawite-(Y) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: black, brownish-black.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals, massive.

Often confused with

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

Often found alongside pilawite-(y)

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

All properties

Chemical formula: CaY₂Fe²⁺Si₂O₁₀
Mohs hardness: 6.5-7
Density: 4.5-4.8 g/cm³
Colors: Black Brownish-black
Streak: White
Luster: Vitreous
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals, Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-500 thumbnail

Where rockhounds find pilawite-(y)

Classic worldwide localities

Poland
Russia
Sweden

Field-hunting tip

Look in granite pegmatites country — that is the host setting where pilawite-(y) typically forms. If you start seeing quartz, feldspar, zircon in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify pilawite-(y)?+

Mohs hardness is 6.5-7. It typically shows a vitreous luster. The streak is white. Common colors include black, brownish-black.

Where is pilawite-(y) found?+

Notable localities include Poland; Russia; Sweden.

How much is pilawite-(y) worth?+

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

Is pilawite-(y) safe to handle?+

This mineral is radioactive. Contains minor amounts of radioactive elements like thorium or uranium; handle with care and wash hands after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like pilawite-(y)?+

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

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

Pilawite-(Y) commonly co-occurs with Quartz, Feldspar, Zircon, Fluorite. Spotting any of these in float or country rock is a useful trip signal.

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

Pilawite-(Y) typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pilawite-(y) used for?+

Pilawite-(Y) is used in collector.

Find pilawite-(y) on the map

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