Trinepheline is a rare orthorhombic polymorph of the common mineral nepheline. It is typically found in alkaline igneous environments and is often difficult to distinguish from common nepheline without advanced X-ray diffraction analysis.

Hardness

5.5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareNepheline family

Trinepheline

Hardness: 5.5-6
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this trinepheline?

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 trinepheline with a known reference. Trinepheline sits at Mohs 5.5-6 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Trinepheline leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Trinepheline typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, gray, yellowish.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Nepheline

Mohs 5.5-6

How to tell apart: Luster reads vitreous on Trinepheline and vitreous to greasy on Nepheline.

Often found alongside trinepheline

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

All properties

Chemical formula: NaAlSiO₄
Mohs hardness: 5.5-6
Density: 2.6-2.7 g/cm³
Colors: Colorless White Gray Yellowish
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Prismatic Crystals
Cleavage: Distinct
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Alkaline Igneous Rocks
Typical price: $20-100 for small study specimens

Where rockhounds find trinepheline

Classic worldwide localities

Kola Peninsula (Russia)
Mont Saint-Hilaire (Canada)

Field-hunting tip

Look in alkaline igneous rocks country — that is the host setting where trinepheline typically forms. If you start seeing nepheline, microcline, aegirine in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify trinepheline?+

Mohs hardness is 5.5-6. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, gray, yellowish.

Where is trinepheline found?+

Notable localities include Kola Peninsula (Russia); Mont Saint-Hilaire (Canada).

How much is trinepheline worth?+

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

What rocks look like trinepheline?+

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

What minerals are found with trinepheline?+

Trinepheline commonly co-occurs with Nepheline, Microcline, Aegirine, Sodalite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does trinepheline form in?+

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

What is trinepheline used for?+

Trinepheline is used in collector, scientific research.

Find trinepheline on the map

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