Quadruphite is a rare phosphate-silicate mineral found predominantly in the hyper-alkaline environments of the Kola Peninsula in Russia. It typically appears as yellowish or colorless tabular crystals embedded within nepheline syenite pegmatites, often associated with other rare alkaline minerals.

Hardness

Mohs

Luster

Vitreous, resinous on fractures, pearly to adamantine on cleavages

Streak

White

Transparency

Translucent to transparent

mineralrareLomonosovite Group family

Quadruphite

Hardness: 5
Luster: Vitreous, resinous on fractures, pearly to adamantine on cleavages
Streak: White
Transparency: Translucent to transparent

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Is this quadruphite?

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 quadruphite with a known reference. Quadruphite sits at Mohs 5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous, resinous on fractures, pearly to adamantine on cleavages.
4
Match the color range
Compare against the expected color range: yellow, brown, colorless.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, massive, granular.

Often confused with

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

mineral

Lomonosovite

Mohs 3-4

How to tell apart: Quadruphite is noticeably harder (Mohs 5 vs. 3-4); streak differs, so Quadruphite leaves white, Lomonosovite leaves light rose-cinnamon.

How to tell apart: Quadruphite is noticeably harder (Mohs 5 vs. 2-3).

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Often found alongside quadruphite

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

All properties

Chemical formula: Na₆Na₂(CaNa)₂Na₂Ti₂Na₂Ti₂(Si₂O₇)₂(PO₄)₄O₄F₂
Mohs hardness: 5
Density: 3.12 g/cm³
Colors: Yellow Brown Colorless
Streak: White
Luster: Vitreous, resinous on fractures, pearly to adamantine on cleavages
Transparency: Translucent to transparent
Crystal system: Triclinic
Crystal habit: Tabular crystals, massive, granular
Cleavage: {001}, perfect; {110} and {100}, less perfect
Rarity: Rare
Uses: Collector
Host rock: In ultra-agpaitic pegmatites in a differentiated alkalic massif

Where rockhounds find quadruphite

Classic worldwide localities

Mt. Alluaiv, Lovozero massif, Kola Peninsula, Russia

Field-hunting tip

Where it forms: In ultra-agpaitic pegmatites in a differentiated alkalic massif. If you start seeing nepheline, sodalite, analcime in float, you are in the right ground. Typical habit: tabular crystals, massive, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify quadruphite?+

Mohs hardness is 5. Luster: vitreous, resinous on fractures, pearly to adamantine on cleavages. The streak is white. Common colors include yellow, brown, colorless.

Where is quadruphite found?+

Notable localities include Mt. Alluaiv, Lovozero massif, Kola Peninsula, Russia.

What rocks look like quadruphite?+

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

What minerals are found with quadruphite?+

Quadruphite commonly co-occurs with Nepheline, Sodalite, Analcime, Potassic feldspar, Albite, Arfvedsonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does quadruphite form in?+

Where it forms: In ultra-agpaitic pegmatites in a differentiated alkalic massif. Working float back to the host body is the standard way to chase a fresh occurrence.

What is quadruphite used for?+

Quadruphite is used in collector.

Find quadruphite on the map

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