Girvasite is a rare phosphate mineral found in the alkaline rocks of the Kovdor Massif. It typically forms as small, tabular, transparent crystals associated with calcite and magnetite in phosphate-rich pegmatites.

Hardness

3.5

Mohs

Luster

Vitreous, silky in aggregates

Streak

White

Transparency

Transparent

mineralrare

Girvasite

Hardness: 3.5
Luster: Vitreous, silky in aggregates
Streak: White
Transparency: Transparent

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Is this girvasite?

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 girvasite with a known reference. Girvasite sits at Mohs 3.5, 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, silky in aggregates.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Apatite

Mohs 5

How to tell apart: Apatite is the harder of the two (Mohs 5 vs. 3.5).

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Often found alongside girvasite

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

All properties

Chemical formula: NaCa₂Mg₃(PO₄)₃(CO₃)(H₂O)₆
Mohs hardness: 3.5
Density: 2.46 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous, silky in aggregates
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular crystals
Cleavage: On {001}, perfect
Rarity: Rare
Uses: Collector
Host rock: A low-temperature hydrothermal mineral filling solution cavities in dolomite carbonatite in a differentiated alkaline massif

Where rockhounds find girvasite

Classic worldwide localities

Zheleznyi iron mine, Kovdor massif, Kola Peninsula, Russia

Field-hunting tip

Where it forms: A low-temperature hydrothermal mineral filling solution cavities in dolomite carbonatite in a differentiated alkaline massif. If you start seeing bobierrite, pyrite, dolomite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify girvasite?+

Mohs hardness is 3.5. Luster: vitreous, silky in aggregates. The streak is white. Common colors include colorless, white.

Where is girvasite found?+

Notable localities include Zheleznyi iron mine, Kovdor massif, Kola Peninsula, Russia.

What rocks look like girvasite?+

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

What minerals are found with girvasite?+

Girvasite commonly co-occurs with Bobierrite, Pyrite, Dolomite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does girvasite form in?+

Where it forms: A low-temperature hydrothermal mineral filling solution cavities in dolomite carbonatite in a differentiated alkaline massif. Working float back to the host body is the standard way to chase a fresh occurrence.

What is girvasite used for?+

Girvasite is used in collector.

Find girvasite on the map

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