Golyshevite is a very rare member of the eudialyte group primarily found in alkaline igneous complexes. It typically presents as small rhombohedral crystals embedded within nepheline-rich pegmatites and is distinguished from other group members through advanced chemical analysis.

Hardness
5.5
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this golyshevite?

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 golyshevite with a known reference. Golyshevite sits at Mohs 5.5, 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.
  • 4
    Match the color range
    Compare against the expected color range: dark reddish brown.
  • 5
    Look at form & habit
    Crystal system: trigonal. Typical habit: rhombohedral crystals.

Often confused with

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

Often found alongside golyshevite

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

All properties

Chemical formula
Na₁₀Ca₉Zr₃Fe₂SiNb(Si₃O₉)₂(Si₉O₂₇)₂(OH)₃(CO₃)·H₂O
Mohs hardness
5.5
Density
2.89 g/cm³
Streak
White
Luster
Vitreous
Transparency
Translucent
Crystal system
Trigonal
Crystal habit
Rhombohedral crystals
Cleavage
Imperfect on {0001}
Rarity
Rare
Uses
Collector
Host rock
In a calcium-rich peralkaline pegmatite

Where rockhounds find golyshevite

Classic worldwide localities

  • Kola Peninsula, Russia

Field-hunting tip

Where it forms: In a calcium-rich peralkaline pegmatite. If you start seeing cancrinite, aegirine-augite, hedenbergite in float, you are in the right ground. Typical habit: rhombohedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify golyshevite?+
Mohs hardness is 5.5. Luster: vitreous. The streak is white. Common colors include dark reddish brown.
Where is golyshevite found?+
Notable localities include Kola Peninsula, Russia.
What rocks look like golyshevite?+
Golyshevite is most often confused with Eudialyte, Kentbrooksite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with golyshevite?+
Golyshevite commonly co-occurs with Cancrinite, Aegirine-augite, Hedenbergite, Orthoclase, Pectolite, Thomsonite-Ca. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does golyshevite form in?+
Where it forms: In a calcium-rich peralkaline pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.
What is golyshevite used for?+
Golyshevite is used in collector.

Find golyshevite on the map

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