Taramellite is a rare barium iron silicate that typically forms dark brown, elongated prismatic crystals. It is most frequently found in metamorphic environments rich in barium, particularly in skarns and localized hydrothermal occurrences. Collectors prize it for its unique chemical composition and association with other rare barium minerals.

Hardness

5.5

Mohs

Luster

Vitreous to silky

Streak

Brown

Transparency

Semitransparent

mineralrareTaramellite Group family

Taramellite

Hardness: 5.5
Luster: Vitreous to silky
Streak: Brown
Transparency: Semitransparent

Is this taramellite?

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 taramellite with a known reference. Taramellite sits at Mohs 5.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: brown.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to silky.
4
Match the color range
Compare against the expected color range: reddish brown, bronze purple, brownish violet.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: fibrous.

Often confused with

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

mineral

Fresnoite

Mohs 3-4

How to tell apart: Taramellite is noticeably harder (Mohs 5.5 vs. 3-4); streak differs, so Taramellite leaves brown, Fresnoite leaves white.

How to tell apart: Streak differs, so Taramellite leaves brown, Benitoite leaves white.

Compare →

Often found alongside taramellite

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

All properties

Chemical formula: Ba₄(Fe,Ti)₄O₂[B₂Si₈O₂₇]Cl₁
Mohs hardness: 5.5
Density: 3.92 g/cm³
Colors: Reddish brownBronze purpleBrownish violet
Streak: Brown
Luster: Vitreous to silky
Transparency: Semitransparent
Crystal system: Orthorhombic
Crystal habit: Fibrous
Rarity: Rare
Uses: Collector
Host rock: In metamorphic rocks rich in barium silicates, in contact with granitic rocks (Candoglia, Italy); in a metamorphosed Fe{Mn orebody (Långban, Sweden)

Where rockhounds find taramellite

Classic worldwide localities

Candoglia, Valle de Toce, Piedmont, Italy
Långban, Värmland, Sweden

Field-hunting tip

Where it forms: In metamorphic rocks rich in barium silicates, in contact with granitic rocks (Candoglia, Italy); in a metamorphosed Fe{Mn orebody (Långban, Sweden). If you start seeing calcite, diopside, actinolite in float, you are in the right ground. Typical habit: fibrous. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify taramellite?+

Mohs hardness is 5.5. Luster: vitreous to silky. The streak is brown. Common colors include reddish brown, bronze purple, brownish violet.

Where is taramellite found?+

Notable localities include Candoglia, Valle de Toce, Piedmont, Italy; Långban, Värmland, Sweden.

What rocks look like taramellite?+

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

What minerals are found with taramellite?+

Taramellite commonly co-occurs with Calcite, Diopside, Actinolite, Celsian, Magnetite, Chalcopyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does taramellite form in?+

Where it forms: In metamorphic rocks rich in barium silicates, in contact with granitic rocks (Candoglia, Italy); in a metamorphosed Fe{Mn orebody (Långban, Sweden). Working float back to the host body is the standard way to chase a fresh occurrence.

What is taramellite used for?+

Taramellite is used in collector.

Find taramellite on the map

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