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, 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.