Mariposite is a green, chromium-rich variety of muscovite mica found in metamorphic rocks, often associated with gold-bearing quartz veins. It is prized by collectors and lapidary artists for its vibrant green color, typically occurring as massive, foliated, or schistose aggregates.

Hardness

2.5-3

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineraluncommonMuscovite family

Mariposite

Also: Chromian Phengitic Muscovite

Hardness: 2.5-3
Luster: Pearly
Streak: White
Transparency: Translucent

Is this mariposite?

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 mariposite with a known reference. Mariposite 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. Mariposite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Mariposite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: bright green, emerald green.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: massive.

Often confused with

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

How to tell apart: Luster reads pearly on Mariposite and greasy on Serpentine.

Compare →

Often found alongside mariposite

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

All properties

Chemical formula: K(Al,Cr)₂(Al,Si)₄O₁₀(OH)₂
Mohs hardness: 2.5-3
Density: 2.7-3.1 g/cm³
Colors: Bright Green Emerald Green
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Massive
Cleavage: Perfect Basal
Rarity: Uncommon
Uses: Decorative, Lapidary, Collector
Host rock: Metamorphic Rocks
Typical price: $5-30 for specimens

Where rockhounds find mariposite

1 mapped spots

Classic worldwide localities

Mariposa County, California, USA
Mother Lode District, California, USA
Nevada, USA

Field-hunting tip

Look in metamorphic rocks country, the host setting where mariposite typically forms. If you start seeing quartz, ankerite, dolomite in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California. Start trip planning there.

Browse 1 U.S. spots for mariposite →

Common questions

How do you identify mariposite?+

Mohs hardness is 2.5-3. It typically shows a pearly luster. The streak is white. Common colors include bright green, emerald green.

Where is mariposite found?+

Notable localities include Mariposa County, California, USA; Mother Lode District, California, USA; Nevada, USA.

Can I find mariposite in the United States?+

RockHoundR maps 1 mariposite rockhounding spots across 1 U.S. states. The top states are California.

How much is mariposite worth?+

Typical asking prices fall in the range of $5-30 for specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like mariposite?+

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

What minerals are found with mariposite?+

Mariposite commonly co-occurs with Quartz, Ankerite, Dolomite, Gold. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mariposite form in?+

Mariposite typically forms in metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mariposite used for?+

Mariposite is used in decorative, lapidary, collector.

Find mariposite on the map

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