Niksergievite is a rare phyllosilicate mineral belonging to the clintonite group, typically found as small, pearly-lustered lamellar crystals or scaly masses. It is primarily known from the Khaidarkan mercury-antimony deposit in Kyrgyzstan where it forms as a rare alteration product. Collectors should look for its characteristic mica-like habit and association with fluorite in hydrothermal vein environments.

Hardness

3.5

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrareClintonite Group family

Niksergievite

Hardness: 3.5
Luster: Pearly
Streak: White
Transparency: Translucent

No image

Is this niksergievite?

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 niksergievite with a known reference. Niksergievite 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. Niksergievite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Niksergievite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: yellow, brown, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: lamellar crystals, scaly aggregates.

Often confused with

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

Often found alongside niksergievite

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

All properties

Chemical formula: (□,Ca,Na)₂(Al,Mg,Fe)₃(Al,Si)₄O₁₀(OH)₂
Mohs hardness: 3.5
Density: 3.08 g/cm³
Colors: Yellow Brown White
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Lamellar Crystals, Scaly Aggregates
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Vein Deposits in Sedimentary Rocks
Typical price: $50-300 per specimen

Where rockhounds find niksergievite

Classic worldwide localities

Khaidarkan, Kyrgyzstan

Field-hunting tip

Look in hydrothermal vein deposits in sedimentary rocks country — that is the host setting where niksergievite typically forms. If you start seeing fluorite, quartz, calcite in float, you are in the right ground. Field specimens usually show a lamellar crystals, scaly aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify niksergievite?+

Mohs hardness is 3.5. It typically shows a pearly luster. The streak is white. Common colors include yellow, brown, white.

Where is niksergievite found?+

Notable localities include Khaidarkan, Kyrgyzstan.

How much is niksergievite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like niksergievite?+

Niksergievite is most often confused with Clintonite, Margarite, Phlogopite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with niksergievite?+

Niksergievite commonly co-occurs with Fluorite, Quartz, Calcite, Stibnite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does niksergievite form in?+

Niksergievite typically forms in hydrothermal vein deposits in sedimentary rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is niksergievite used for?+

Niksergievite is used in collector.

Find niksergievite on the map

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