Puninite is a rare sodium copper sulfate that forms emerald-green crusts of irregularly-shaped grains. It occurs in a sublimate around an active fumarole. Associated minerals include tenorite, hematite and anhydrite. It was first described from Glavnaya Tenoritovaya fumarole, Tolbachik volcano, Kamchatka, Russia.
Is this puninite?
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 puninite with a known reference. Puninite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Puninite leaves a greenish streak.
- 3Read the lusterHold the specimen under a strong light. Puninite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: emerald-green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: crusts of irregularly-shaped grains.
Often confused with
Puninite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Eudialyte is the harder of the two (Mohs 5-6 vs. 2-3); streak differs, so Puninite leaves greenish, Eudialyte leaves white.
How to tell apart: Streak differs, so Puninite leaves greenish, Lamprophyllite leaves white; luster reads vitreous on Puninite and submetallic on Lamprophyllite.
Often found alongside puninite
Minerals reported to co-occur with puninite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Cu₃O(SO₄)₃
- Mohs hardness
- 2-3
- Density
- 3.298 g/cm³
- Colors
- Streak
- Greenish
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Crusts of Irregularly-shaped Grains
- Cleavage
- {100}, Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Pegmatites
Where rockhounds find puninite
Classic worldwide localities
- Khibiny Massif, Kola Peninsula, Russia
Field-hunting tip
Look in alkaline pegmatites country, the host setting where puninite typically forms. If you start seeing nepheline, aegirine, titanite in float, you are in the right ground. Field specimens usually show a crusts of irregularly-shaped grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify puninite?+
Where is puninite found?+
What rocks look like puninite?+
What minerals are found with puninite?+
What kind of rock does puninite form in?+
What is puninite used for?+
Find puninite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
