Moskvinite-(Y) is an exceptionally rare silicate mineral found in the hyperalkaline pegmatites of the Kola Peninsula. It typically occurs as small tabular crystals associated with other rare alkaline minerals. It is a prized addition for advanced systematic mineral collectors due to its restricted geographical occurrence.

Hardness
5
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this moskvinite-(y)?

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 moskvinite-(y) with a known reference. Moskvinite-(Y) 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.
  • 4
    Match the color range
    Compare against the expected color range: white.
  • 5
    Look at form & habit
    Crystal system: orthorhombic. Typical habit: irregular grains.

Often confused with

Moskvinite-(Y) vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside moskvinite-(y)

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

All properties

Chemical formula
Na₂KYSi₆O₁₅
Mohs hardness
5
Density
2.91 g/cm³
Colors
Streak
White
Luster
Vitreous
Transparency
Transparent
Crystal system
Orthorhombic
Crystal habit
Irregular grains
Cleavage
None
Rarity
Rare
Uses
Collector
Host rock
In a boulder of coarse-grained, reedmergnerite-bearing pegmatite in the moraine of the Dara-i-Pioz glacier, Alai mountain ridge, Tien-Shan Mountains, northern Tajikistan

Where rockhounds find moskvinite-(y)

Classic worldwide localities

  • Dara-i-Pioz moraine, Tien-Shan Mountains, Tajikistan
  • Drill core at Kvanefjeld, Ilímaussaq alkaline complex, South Greenland

Field-hunting tip

Where it forms: In a boulder of coarse-grained, reedmergnerite-bearing pegmatite in the moraine of the Dara-i-Pioz glacier, Alai mountain ridge, Tien-Shan Mountains, northern Tajikistan. If you start seeing shibkovite, nordite-, leucophanite in float, you are in the right ground. Typical habit: irregular grains. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify moskvinite-(y)?+
Mohs hardness is 5. Luster: vitreous. The streak is white. Common colors include white.
Where is moskvinite-(y) found?+
Notable localities include Dara-i-Pioz moraine, Tien-Shan Mountains, Tajikistan; Drill core at Kvanefjeld, Ilímaussaq alkaline complex, South Greenland.
What rocks look like moskvinite-(y)?+
Moskvinite-(Y) is most often confused with Eudialyte, Khibinskite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with moskvinite-(y)?+
Moskvinite-(Y) commonly co-occurs with Shibkovite, Nordite-, Leucophanite, Microcline, Albite, Hyalotekite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does moskvinite-(y) form in?+
Where it forms: In a boulder of coarse-grained, reedmergnerite-bearing pegmatite in the moraine of the Dara-i-Pioz glacier, Alai mountain ridge, Tien-Shan Mountains, northern Tajikistan. Working float back to the host body is the standard way to chase a fresh occurrence.
What is moskvinite-(y) used for?+
Moskvinite-(Y) is used in collector.

Find moskvinite-(y) on the map

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