Nanpingite is a rare cesium-rich mica typically found as small, platy inclusions or aggregates within highly evolved pegmatites. Because it closely resembles common muscovite, it is often identified primarily through chemical analysis or specialized X-ray diffraction in geological research settings.

Hardness

2.5

Mohs

Luster

Pearly

Streak

White

Transparency

Transparent

mineralrareMica Group family

Nanpingite

Hardness: 2.5
Luster: Pearly
Streak: White
Transparency: Transparent

Is this nanpingite?

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 nanpingite with a known reference. Nanpingite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Nanpingite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Nanpingite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: colorless, white, pale yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy or micaceous aggregates.

Often confused with

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

Often found alongside nanpingite

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

All properties

Chemical formula: Cs(AlMg)₂Si₃AlO₁₀(OH)₂
Mohs hardness: 2.5
Density: 3.01 g/cm³
Colors: Colorless White Pale Yellow
Streak: White
Luster: Pearly
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy or Micaceous Aggregates
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find nanpingite

Classic worldwide localities

Nanping, Fujian Province, China
Tanco Mine, Manitoba, Canada

Field-hunting tip

Look in granite pegmatites country — that is the host setting where nanpingite typically forms. If you start seeing quartz, albite, pollucite in float, you are in the right ground. Field specimens usually show a platy or micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify nanpingite?+

Mohs hardness is 2.5. It typically shows a pearly luster. The streak is white. Common colors include colorless, white, pale yellow.

Where is nanpingite found?+

Notable localities include Nanping, Fujian Province, China; Tanco Mine, Manitoba, Canada.

How much is nanpingite 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 nanpingite?+

Nanpingite is most often confused with Muscovite, Polylithionite, Lepidolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with nanpingite?+

Nanpingite commonly co-occurs with Quartz, Albite, Pollucite, Spodumene. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does nanpingite form in?+

Nanpingite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is nanpingite used for?+

Nanpingite is used in collector.

Find nanpingite on the map

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