Shungite is a rare, carbonaceous rock primarily found in the Karelia region of Russia, near Lake Onega. This ancient material is unique because its composition includes a naturally occurring form of hollow, spherical carbon molecules called fullerenes. The presence of fullerenes, which are highly conductive, sets shungite apart from most other rocks and minerals. Because of its scarcity and unique properties, the market is frequently flooded with imitations. Verifying the authenticity of this distinct rock requires a practical, three-part approach focusing on its observable characteristics, its electrical signature, and a comparison with common fake materials.
Visual Properties and Shungite Grades
Authentic shungite is commercially categorized into two main grades, primarily based on carbon content and appearance. Noble, or Elite, shungite is the rarest and highest grade, containing a carbon percentage that can range from 70 to over 98 percent. This high carbon level gives Elite shungite a distinct, semi-metallic, and silvery-gray luster, making it look almost polished even in its raw, unshaped form. Elite shungite is also relatively brittle and cannot be easily shaped or polished, which is why it is often sold as rough, irregularly shaped pieces.
The more common type is Black, or Regular, shungite, which typically has a lower carbon concentration, generally ranging from 30 to 70 percent. This grade is matte black, can be polished to a dark sheen, and is used to create most shungite products like pyramids, spheres, and jewelry.
A simple visual check involves looking for mineral inclusions, which are common in authentic shungite, particularly the regular grade. These inclusions often appear as white or gold veins, typically quartz or pyrite, that run through the black matrix. Due to its high carbon content, genuine shungite will often leave a faint black or gray residue on the skin or clothing when handled, which is a key initial indicator of its composition.
The Electrical Conductivity Test
The most definitive method for testing authenticity is the electrical conductivity test, a property unusual for a stone. Shungite’s conductivity stems from its carbon matrix, which allows electrons to move freely, making it possible to complete an electrical circuit using the stone itself as a conductor.
You can perform this test using a basic digital multimeter set to measure resistance, indicated by the Ohm symbol. First, check the multimeter by touching the two probes together; the reading should drop to zero or near-zero, confirming the device is working and the circuit is closed. Next, place the shungite sample on a non-conductive surface, such as wood or plastic, to prevent interference with the reading.
Touch the metallic tip of one probe to one point on the shungite and the other probe tip to a different point on the stone, ensuring good contact. Authentic shungite will show a very low resistance reading, often dropping to just a few Ohms, or simply completing the circuit and producing a continuity beep. If the reading remains at one, which indicates an open circuit, the material is not electrically conductive and is likely fake.
Alternatively, a simple circuit can be constructed using a small battery, a light bulb, and two wires; if the stone is placed between the wires and the bulb lights up, the sample is genuine.
Identifying Common Imitations
Many imitations attempt to mimic the visual characteristics of shungite but fail the definitive conductivity test. One of the most common fakes is anthracite coal, which is also black and carbon-rich but lacks the unique fullerene structure, meaning it will not conduct electricity. Dyed black materials or plastic resins are also used, but these often feel warmer to the touch than natural stone and may show mold marks or air bubbles under close inspection.
Density and Hardness Tests
A density test can provide verification, as genuine shungite is relatively dense, with a specific gravity ranging from 1.9 to 2.3 depending on its carbon content. Fakes made of lighter materials, like certain plastics or porous coal, will feel too light for their size.
You can also perform a simple scratch test, noting that shungite is relatively soft, registering around 3.5 on the Mohs scale of hardness. While shungite is soft enough to be scratched by a harder material like glass, a fake made of hematite, which is sometimes used as an imitation, will leave a reddish streak when rubbed against an unglazed porcelain plate. Authentic shungite, however, always produces a dark gray or black streak, matching its composition.