Tusionite is a rare manganese tin borate mineral typically found in granitic pegmatites. It forms glassy, rhombohedral crystals that are highly sought after by advanced collectors for their rarity and aesthetic appeal.

Hardness

5-5.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Tusionite

Hardness: 5-5.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this tusionite?

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 tusionite with a known reference. Tusionite sits at Mohs 5-5.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Tusionite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Tusionite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown, pink, colorless.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular to rhombohedral crystals.

Often confused with

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

mineral

Calcite

Mohs 3

How to tell apart: Tusionite is noticeably harder (Mohs 5-5.5 vs. 3).

How to tell apart: Tusionite is noticeably harder (Mohs 5-5.5 vs. 3.5-4).

Compare →

Often found alongside tusionite

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

All properties

Chemical formula: MnSn(BO₃)₂
Mohs hardness: 5-5.5
Density: 3.52 g/cm³
Colors: Yellow Brown Pink Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Tabular to Rhombohedral Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Pegmatites
Typical price: $100-500 per specimen

Where rockhounds find tusionite

Classic worldwide localities

Tadjikistan
Russia

Field-hunting tip

Look in pegmatites country — that is the host setting where tusionite typically forms. If you start seeing quartz, cassiterite, muscovite in float, you are in the right ground. Field specimens usually show a tabular to rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tusionite?+

Mohs hardness is 5-5.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, brown, pink, colorless.

Where is tusionite found?+

Notable localities include Tadjikistan; Russia.

How much is tusionite worth?+

Typical asking prices fall in the range of $100-500 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like tusionite?+

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

What minerals are found with tusionite?+

Tusionite commonly co-occurs with Quartz, Cassiterite, Muscovite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tusionite form in?+

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

What is tusionite used for?+

Tusionite is used in collector.

Find tusionite on the map

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