Yixunite is an extremely rare platinum-indium alloy primarily known from placer deposits in the Yixun River area of China. It typically appears as microscopic anhedral grains associated with other platinum-group minerals in heavy mineral concentrates. Due to its extreme rarity and minute grain size, it is almost exclusively of interest to advanced mineralogists and systematic collection suites.

Hardness
5.8
Mohs
Luster
Metallic
Streak
Black
Transparency
Opaque

Is this yixunite?

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 yixunite with a known reference. Yixunite sits at Mohs 5.8, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Streak: black.
  • 3
    Read the luster
    Hold the specimen under a strong light. Luster: metallic.
  • 4
    Match the color range
    Compare against the expected color range: bright white.
  • 5
    Look at form & habit
    Crystal system: cubic. Typical habit: globular.

Often confused with

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

Often found alongside yixunite

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

All properties

Chemical formula
Pt₃In
Mohs hardness
5.8
Density
18.21-18.32 g/cm³
Colors
Bright white
Streak
Black
Luster
Metallic
Transparency
Opaque
Crystal system
Cubic
Crystal habit
Globular
Cleavage
None
Rarity
Rare
Uses
Collector
Host rock
In a contact metasomatic Co–Cu–Pt-bearing vein in garnet-amphibole pyroxenite in contact with anorthosite and granite

Where rockhounds find yixunite

Classic worldwide localities

  • Near the village of Damiao and the Yixun River, about 370 km N of Beijing, People's Republic of China (type locality)

Field-hunting tip

Where it forms: In a contact metasomatic Co–Cu–Pt-bearing vein in garnet-amphibole pyroxenite in contact with anorthosite and granite. If you start seeing moncheite, sperrylite, cooperite in float, you are in the right ground. Typical habit: globular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yixunite?+
Mohs hardness is 5.8. Luster: metallic. The streak is black. Common colors include bright white.
Where is yixunite found?+
Notable localities include Near the village of Damiao and the Yixun River, about 370 km N of Beijing, People's Republic of China (type locality).
What rocks look like yixunite?+
Yixunite is most often confused with Platinum, Sperrylite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with yixunite?+
Yixunite commonly co-occurs with Moncheite, Sperrylite, Cooperite, Damiaoite, Cobaltian malanite, Bornite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does yixunite form in?+
Where it forms: In a contact metasomatic Co–Cu–Pt-bearing vein in garnet-amphibole pyroxenite in contact with anorthosite and granite. Working float back to the host body is the standard way to chase a fresh occurrence.
What is yixunite used for?+
Yixunite is used in collector.

Find yixunite on the map

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