Tiettaite is a rare potassium sodium iron silicate, typically grayish white. It occurs in unweathered ultra-alkalic pegmatites in an alkalic massif. It was first described from Mts. Koashva and Rasvumchorr, Khibiny massif, Kola Peninsula, Russia.

Hardness

3-4

Mohs

Luster

Vitreous to Silky

Streak

[white

Transparency

Transparent

mineralrare

Tiettaite

Hardness: 3-4
Luster: Vitreous to Silky
Streak: [white
Transparency: Transparent

Is this tiettaite?

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 tiettaite with a known reference. Tiettaite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Tiettaite leaves a [white streak.
3
Read the luster
Hold the specimen under a strong light. Tiettaite typically shows a vitreous to silky luster.
4
Match the color range
Compare against the expected color range: grayish white.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: massive, aggregates.

Often confused with

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

mineral

Searlesite

Mohs 3.5

How to tell apart: Streak differs, so Tiettaite leaves [white, Searlesite leaves white; luster reads vitreous to silky on Tiettaite and vitreous on Searlesite.

Compare →

Often found alongside tiettaite

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

All properties

Chemical formula: K₄Na₁₂Fe³⁺₂Si₁₆O₄₁(OH)₄·2H₂O
Mohs hardness: 3-4
Density: 2.42 g/cm³
Colors: Grayish White
Streak: [white
Luster: Vitreous to Silky
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Massive, Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Alkaline Pegmatites

Where rockhounds find tiettaite

Classic worldwide localities

Khibiny Massif, Kola Peninsula, Russia

Field-hunting tip

Look in alkaline pegmatites country, the host setting where tiettaite typically forms. If you start seeing aegirine, khibinskite, natrolite in float, you are in the right ground. Field specimens usually show a massive, aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tiettaite?+

Mohs hardness is 3-4. It typically shows a vitreous to silky luster. The streak is [white. Common colors include grayish white.

Where is tiettaite found?+

Notable localities include Khibiny Massif, Kola Peninsula, Russia.

What rocks look like tiettaite?+

Tiettaite is most often confused with Searlesite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with tiettaite?+

Tiettaite commonly co-occurs with Aegirine, Khibinskite, Natrolite, Lomonosovite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tiettaite form in?+

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

What is tiettaite used for?+

Tiettaite is used in collector.

Find tiettaite on the map

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