Boromuscovite is a rare boron-rich member of the mica group, structurally analogous to muscovite. It typically appears as colorless to pale-colored platy crystals or foliated aggregates, usually found in complex pegmatitic or metamorphic environments where boron enrichment occurs.

Hardness

2.5-3

Mohs

Luster

Pearly

Streak

White

Transparency

Transparent

mineralrareMica Group family

Boromuscovite

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

Is this boromuscovite?

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 boromuscovite with a known reference. Boromuscovite 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. Boromuscovite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Boromuscovite 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, foliated, micaceous masses.

Often confused with

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

Often found alongside boromuscovite

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

All properties

Chemical formula: KAl₂(AlSi₃O₁₀)(OH)₂
Mohs hardness: 2.5-3
Density: 2.8-2.9 g/cm³
Colors: Colorless White Pale Yellow
Streak: White
Luster: Pearly
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy, Foliated, Micaceous Masses
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Metamorphic Rocks, Pegmatites
Typical price: $20-100 per specimen

Where rockhounds find boromuscovite

Classic worldwide localities

Sarany deposit, Russia
Finland
Brazil

Field-hunting tip

Look in metamorphic rocks, pegmatites country, the host setting where boromuscovite typically forms. If you start seeing quartz, feldspar, tourmaline in float, you are in the right ground. Field specimens usually show a platy, foliated, micaceous masses habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify boromuscovite?+

Mohs hardness is 2.5-3. It typically shows a pearly luster. The streak is white. Common colors include colorless, white, pale yellow.

Where is boromuscovite found?+

Notable localities include Sarany deposit, Russia; Finland; Brazil.

How much is boromuscovite worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like boromuscovite?+

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

What minerals are found with boromuscovite?+

Boromuscovite commonly co-occurs with Quartz, Feldspar, Tourmaline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does boromuscovite form in?+

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

What is boromuscovite used for?+

Boromuscovite is used in collector, scientific research.

Find boromuscovite on the map

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