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.
Is this genplesite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch genplesite with a known reference. Genplesite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Genplesite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Genplesite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals.
Often confused with
Genplesite vs. its common look-alikes — and how to tell them apart in the field.
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
- CaSn(OH)₆
- Mohs hardness
- 3.5
- Density
- 2.42 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Skarn Deposits
- Typical price
- $50-500 depending on specimen quality and size
Where rockhounds find genplesite
Classic worldwide localities
- Pitkyaranta, Karelia, Russia
Field-hunting tip
Look in skarn deposits country — that is the host setting where genplesite typically forms. If you start seeing cassiterite, calcite, chalcopyrite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.






