Tokkoite is a rare potassium-calcium silicate mineral found primarily in the alkaline rocks of the Murun Massif in Siberia. It typically appears as yellowish-brown fibrous or radiating aggregates and is often associated with the mineral tinaksite. Due to its limited distribution, it is highly sought after by systematic mineral collectors.

Hardness

5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrare

Tokkoite

Hardness: 5-6
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this tokkoite?

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 tokkoite with a known reference. Tokkoite sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Tokkoite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Tokkoite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown, yellow-brown.
5
Look at form & habit
Crystal system: triclinic. Typical habit: fibrous, massive, radiating clusters.

Often confused with

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

How to tell apart: Luster reads vitreous on Tokkoite and vitreous to pearly on Tinaksite.

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Often found alongside tokkoite

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

All properties

Chemical formula: K₂Ca₄Si₇O₁₇(OH,F)₂
Mohs hardness: 5-6
Density: 2.9 g/cm³
Colors: Yellow Brown Yellow-brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Fibrous, Massive, Radiating Clusters
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Alkaline Igneous Rocks
Typical price: $20-150 for small specimens

Where rockhounds find tokkoite

Classic worldwide localities

Tokko River, Murun Massif, Russia
Chara-Tokko district, Siberia

Field-hunting tip

Look in alkaline igneous rocks country, the host setting where tokkoite typically forms. If you start seeing tinaksite, potassian richerite, aegirine in float, you are in the right ground. Field specimens usually show a fibrous, massive, radiating clusters habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tokkoite?+

Mohs hardness is 5-6. It typically shows a vitreous luster. The streak is white. Common colors include yellow, brown, yellow-brown.

Where is tokkoite found?+

Notable localities include Tokko River, Murun Massif, Russia; Chara-Tokko district, Siberia.

How much is tokkoite worth?+

Typical asking prices fall in the range of $20-150 for small specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like tokkoite?+

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

What minerals are found with tokkoite?+

Tokkoite commonly co-occurs with Tinaksite, Potassian Richerite, Aegirine, Kalsilite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tokkoite form in?+

Tokkoite typically forms in alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tokkoite used for?+

Tokkoite is used in collector.

Find tokkoite on the map

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