Yimengite is a rare potassium-rich oxide mineral typically found as small, black, hexagonal tabular crystals within diamond-bearing kimberlite pipes. It is primarily recognized by collectors of rare earth and oxide minerals, as it is only known from specific kimberlite occurrences in China.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareMagnetoplumbite Group family

Yimengite

Hardness: 6
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this yimengite?

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 yimengite with a known reference. Yimengite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Yimengite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Yimengite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: tabular crystals, hexagonal plates.

Often confused with

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

How to tell apart: Luster reads metallic on Yimengite and submetallic on Manaccanite.

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Often found alongside yimengite

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

All properties

Chemical formula: K(Cr,Ti,Fe,Mg,Al)₁₂O₁₉
Mohs hardness: 6
Density: 4.57 g/cm³
Colors: Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Tabular Crystals, Hexagonal Plates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Kimberlite
Typical price: $50-300 per specimen

Where rockhounds find yimengite

Classic worldwide localities

Fuxian, Shandong Province, China
Kimberlite pipes of the Shandong region

Field-hunting tip

Look in kimberlite country, the host setting where yimengite typically forms. If you start seeing diamond, pyrope, chromite in float, you are in the right ground. Field specimens usually show a tabular crystals, hexagonal plates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yimengite?+

Mohs hardness is 6. It typically shows a metallic luster. The streak is black. Common colors include black.

Where is yimengite found?+

Notable localities include Fuxian, Shandong Province, China; Kimberlite pipes of the Shandong region.

How much is yimengite 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.

What rocks look like yimengite?+

Yimengite is most often confused with Magnetoplumbite, Hawthorneite, Manaccanite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with yimengite?+

Yimengite commonly co-occurs with Diamond, Pyrope, Chromite, Phlogopite, Enstatite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does yimengite form in?+

Yimengite typically forms in kimberlite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is yimengite used for?+

Yimengite is used in collector.

Find yimengite on the map

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