Genplesite is a rare tin-bearing calcium hydroxide mineral typically found as small, clear, tabular crystals in skarn environments. It is predominantly known from the Pitkyaranta mining district, where it forms alongside various tin and sulfide minerals. Due to its extreme rarity and small crystal size, it is almost exclusively sought after by advanced systematic mineral collectors.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Genplesite

Hardness: ~3
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this genplesite?

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 genplesite with a known reference. Genplesite sits at Mohs ~3, 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: colorless.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: tabular crystals.

Often confused with

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

How to tell apart: Stannite is the harder of the two (Mohs 4 vs. ~3); streak differs, so Genplesite leaves white, Stannite leaves blackish; luster reads vitreous on Genplesite and metallic on Stannite.

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Often found alongside genplesite

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

All properties

Chemical formula: Ca₃Sn(SO₄)₂(OH)₆·3H₂O
Mohs hardness: ~3
Density: 2.78 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Tabular crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: A late-stage, low-temperature hydrothermal mineral in cavities in massive chalcopyrite

Where rockhounds find genplesite

Classic worldwide localities

No. 1 shaft (level 750-m), Oktyabr’skoe Cu-Ni-Pd-Pt deposit (Oktyabr’sky mine), Talnakh, Norilsk district, Siberia, Russia

Field-hunting tip

Where it forms: A late-stage, low-temperature hydrothermal mineral in cavities in massive chalcopyrite. If you start seeing greenalite, chamosite, pectolite 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 genplesite?+

Mohs hardness is ~3. Luster: vitreous. The streak is white. Common colors include colorless.

Where is genplesite found?+

Notable localities include No. 1 shaft (level 750-m), Oktyabr’skoe Cu-Ni-Pd-Pt deposit (Oktyabr’sky mine), Talnakh, Norilsk district, Siberia, Russia.

What rocks look like genplesite?+

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

What minerals are found with genplesite?+

Genplesite commonly co-occurs with Greenalite, Chamosite, Pectolite, Ferroactinolite, Calcite, Fluorapatite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does genplesite form in?+

Where it forms: A late-stage, low-temperature hydrothermal mineral in cavities in massive chalcopyrite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is genplesite used for?+

Genplesite is used in collector.

Find genplesite on the map

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