Ximengite is a rare bismuth phosphate mineral that typically forms as small, tabular crystals or fine granular masses. It is primarily identified by its occurrence in specific hydrothermal environments and requires mineralogical analysis for definitive identification due to its similarity to other rare bismuth species.

Hardness

4.5

Mohs

Luster

Vitreous to greasy

Streak

White

Transparency

Transparent

mineralrare

Ximengite

Hardness: 4.5
Luster: Vitreous to greasy
Streak: White
Transparency: Transparent

No image

Is this ximengite?

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 ximengite with a known reference. Ximengite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to greasy.
4
Match the color range
Compare against the expected color range: colorless.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular crystals, granular aggregates.

Often confused with

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

mineral

Monazite

Mohs 5-5.5

How to tell apart: Luster reads vitreous to greasy on Ximengite and resinous on Monazite.

How to tell apart: Luster reads vitreous to greasy on Ximengite and resinous or greasy to vitreous on Cheralite.

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Often found alongside ximengite

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

All properties

Chemical formula: BiPO₄
Mohs hardness: 4.5
Density: 5.534 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous to greasy
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Tabular crystals, granular aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: An alteration product of bismuthinite in a tin deposit

Where rockhounds find ximengite

Classic worldwide localities

Undefined locality in Ximeng Co., about 420 km southwest of Kunming, Yunnan Province, China (type locality)

Field-hunting tip

Where it forms: An alteration product of bismuthinite in a tin deposit. If you start seeing bismuthinite, waylandite, monazite in float, you are in the right ground. Typical habit: tabular crystals, granular aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ximengite?+

Mohs hardness is 4.5. Luster: vitreous to greasy. The streak is white. Common colors include colorless.

Where is ximengite found?+

Notable localities include Undefined locality in Ximeng Co., about 420 km southwest of Kunming, Yunnan Province, China (type locality).

Is ximengite safe to handle?+

Contains bismuth, which is generally low toxicity, but handle with care as it is an heavy metal mineral; avoid inhalation of dust when trimming or processing.

What rocks look like ximengite?+

Ximengite is most often confused with Monazite, Cheralite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with ximengite?+

Ximengite commonly co-occurs with Bismuthinite, Waylandite, Monazite, Cassiterite, Tourmaline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ximengite form in?+

Where it forms: An alteration product of bismuthinite in a tin deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ximengite used for?+

Ximengite is used in collector.

Find ximengite on the map

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