Gem library
Shungite
Karelian carbon, two billion years old
Shungite is a rock made almost entirely of carbon, formed about two billion years ago, long before complex life existed. Its origin is still debated, and that is what makes it scientifically interesting, quite apart from everything else it is credited with.
- Hardness (Mohs)
- 3.5 – 4
- Density
- 1.80 – 2.10
- Crystal system
- Amorphous
- Refractive index
- opaque, not measurable
- Cleavage
- None
Mineralogical identity
- Family
- Carbonaceous rock (non-crystalline)
- Species
- Shungite
- Variety
- Type I (elite, 98 % carbon) to type III
- Chemical formula
- C (30 to 98 %), with silica and silicates
- Crystal system
- Amorphous (non-graphitic carbon)
- Classification
- Rock
- Rarity
- Uncommon
- Indicative price
- €0.10 – 3/g (elite shungite: €1 – 10/g)
Etymology
From the village of Shunga in Russian Karelia, near Lake Onega, where the rock was first described in the eighteenth century.
Physical & optical properties
- Hardness (Mohs)
- 3.5 – 4
- Density
- 1.80 – 2.10
- Refractive index
- opaque, not measurable
- Birefringence
- none
- Cleavage
- None
- Fracture
- Conchoidal
- Lustre
- Matt to submetallic
- Diaphaneity
- Opaque
- UV fluorescence
- None
- Pleochroism
- None
- Colours
- black, steel grey, silvery black
Formation, geology & history
Two billion years, and a puzzle
The Karelian deposits formed in the Palaeoproterozoic, around two billion years ago. At that time life amounted to bacteria and algae. Where, then, does such a mass of organic carbon come from? The leading hypothesis is an accumulation of microbial matter in a shallow marine basin, buried and then transformed by heat. Other researchers have proposed a volcanic or even meteoritic origin, but the isotopic signature of the carbon points firmly to biology. The deposit is associated with the Lomagundi event, a global anomaly in the carbon cycle following the Great Oxidation of the atmosphere: shungite is a direct witness to that period.
Fullerenes: what is established, and what is not
Shungite owes its recent fame to the discovery, in 1992, of natural fullerenes in some samples: cage-shaped carbon molecules of the C₆₀ type, whose laboratory discovery earned a Nobel Prize in chemistry in 1996. The fact is documented, but it calls for two qualifications. First, the content is very low, of the order of a few thousandths of a percent, and absent from most samples. Second, the presence of a molecule in a rock says nothing about what that rock would do to an organism. The trade has stretched this well past what the scientific literature supports.
What shungite really does, and does not
Shungite conducts electricity, remarkable for a rock, and that is the basis of its industrial use as an additive in certain absorbing materials. It is also used in Russia in water filters: porous carbon adsorbs organic compounds, as activated charcoal does. On the other hand, the common claims about protection from electromagnetic fields rest on no solid data: a small disc of rock on a phone screens nothing measurable. That has to be said plainly, and it takes nothing away from the geological interest of the stone.
How to recognise it
- It marks your fingers, or does notLow-carbon shungite leaves a blackish smear like graphite. Elite shungite is bright, brittle and does not mark: a clue to the type.
- LightnessDensity around 2, clearly less than obsidian (2.4) or polished jet in a setting. For the same bulk it feels hollow.
- ConductivityA multimeter set to continuity across two points of an elite sample gives a reading. No other black stone in the trade conducts.
Imitations, treatments & confusions
- Black resin filled with powderVery common on cheap pyramids and discs. Too regular a surface, moulded, sometimes a seam line, and no conductivity.
- Black shale or slateSold as type III shungite. Denser, layered, and they do not conduct.
- «Elite» shungite that is notElite shungite is a tiny fraction of production. A whole batch sold as elite at a low price is not.
Deposits & origins
Russia (Karelia, Lake Onega: the only significant deposit in the world), traces in Kazakhstan and India
Care & precautions
- Rinse with clear water and dry. Rough stones shed powder the first few times, which is normal.
- No soap or detergent on stones intended for a water filter.
- Fears neither light nor ordinary heat.
- Store apart, carbon dust marks everything it touches.
Traditions & crystal healing
- Chakras
- Root
- Zodiac signs
- Capricorn · Scorpio
- Element
- Earth
It is made into a stone of grounding and protection, very often presented as a shield against electromagnetic fields. On that last point tradition goes well beyond anything physics supports, and it is better to know it. Cultural heritage, never medicine.
The virtues described here belong to tradition and cultural heritage. They are in no way medical advice and never replace a consultation.
Frequently asked questions
Does shungite protect against phone radiation?
No. No serious data show it and physics does not explain it: a disc a few centimetres across does not screen radiation. It is the most widespread claim about this stone, and the least founded.
Can shungite go in drinking water?
It is a traditional Russian use, and porous carbon does adsorb some organic compounds, like activated charcoal. Rinse the stone well first, and do not rely on it as a purification system.
Elite versus ordinary shungite?
Carbon content: about 98 % for elite, bright and brittle, against 30 to 60 % for the common types, matt and compact. Only the ordinary kind is carved.
Tools for this stone
Shungite: only the tools this stone actually concerns, each carrying the value read on this page.