Yttrotungstite-(Y) is an extremely rare secondary tungsten mineral typically found as an alteration product of ferberite or scheelite in oxidized zones. It generally forms soft, platy, or earthy masses that display a distinct pearly luster on cleavage surfaces.

Hardness
2.5-3
Mohs
Luster
Pearly
Streak
Yellow
Transparency
Translucent

Is this yttrotungstite-(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 yttrotungstite-(y) with a known reference. Yttrotungstite-(Y) sits at Mohs 2.5-3 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Yttrotungstite-(Y) leaves a yellow streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Yttrotungstite-(Y) typically shows a pearly luster.
  • 4
    Match the color range
    Compare against the expected color range: yellow, brownish-yellow, greenish-yellow.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: platy, fibrous aggregates, massive.

Often confused with

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

Often found alongside yttrotungstite-(y)

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

All properties

Chemical formula
Y(WO₃)(OH)₃
Mohs hardness
2.5-3
Density
5.5-5.6 g/cm³
Streak
Yellow
Luster
Pearly
Transparency
Translucent
Crystal system
Monoclinic
Crystal habit
Platy, Fibrous Aggregates, Massive
Cleavage
Perfect On {001}
Rarity
Rare
Uses
Collector
Host rock
Weathered Granite Pegmatites and Hydrothermal Tin-tungsten Veins
Typical price
$50-300 per specimen

Where rockhounds find yttrotungstite-(y)

Classic worldwide localities

  • Pulacayo, Bolivia
  • Kinta Valley, Malaysia
  • Kigali, Rwanda

Field-hunting tip

Look in weathered granite pegmatites and hydrothermal tin-tungsten veins country — that is the host setting where yttrotungstite-(y) typically forms. If you start seeing ferberite, scheelite, tungstite in float, you are in the right ground. Field specimens usually show a platy, fibrous aggregates, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yttrotungstite-(y)?+
Mohs hardness is 2.5-3. It typically shows a pearly luster. The streak is yellow. Common colors include yellow, brownish-yellow, greenish-yellow.
Where is yttrotungstite-(y) found?+
Notable localities include Pulacayo, Bolivia; Kinta Valley, Malaysia; Kigali, Rwanda.
How much is yttrotungstite-(y) worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
Is yttrotungstite-(y) safe to handle?+
This mineral is radioactive. Contains rare earth elements and may contain thorium inclusions; handle with care and wash hands after contact to avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like yttrotungstite-(y)?+
Yttrotungstite-(Y) is most often confused with Tungstite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with yttrotungstite-(y)?+
Yttrotungstite-(Y) commonly co-occurs with Ferberite, Scheelite, Tungstite, Kaolinite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does yttrotungstite-(y) form in?+
Yttrotungstite-(Y) typically forms in weathered granite pegmatites and hydrothermal tin-tungsten veins. Working float back to the host body is the standard way to chase a fresh occurrence.
What is yttrotungstite-(y) used for?+
Yttrotungstite-(Y) is used in collector.

Find yttrotungstite-(y) on the map

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