Leningradite

Chemical formula: Pb²⁺Cu²⁺₃(V⁵⁺O₄)₂Cl₂

Leningradite is a rare lead copper vanadate, distinguished by its intense red color and origin from volcanic exhalations.

## Characteristics Leningradite is a rare mineral from the vanadate group, chemically classified as a lead copper chlorovanadate. It forms small, tabular or platy crystals, rarely exceeding 1 mm in length. Its most characteristic feature is its intense, bright red color, which makes it easily noticeable despite its small size. It typically occurs as single crystals or small aggregates on the surface of porous, volcanic rock (scoria). ## Physical Properties This mineral has a Mohs hardness of 4.5. It exhibits a luster described as submetallic to greasy. It is opaque. Its density is relatively high at 4.81 g/cm³, which is typical for lead-bearing minerals. ## Colors and Varieties Leningradite occurs in a single, characteristic color – intense red. No color varieties or commercial forms are known. ## History and Name The mineral was first described in 1988 by L.P. Vergasova and S.K. Filatov. Its name comes from the city of Leningrad (now St. Petersburg) in Russia, in recognition of the contribution of mineralogists from the local university to the study of volcanic exhalation products. ## Applications Due to its extreme rarity and small crystal size, leningradite has no industrial applications. It is solely an object of scientific interest and for advanced collectors specializing in rare minerals or minerals from specific localities.

Properties

Mohs hardness
4.5
Luster
Sub-Metallic
Streak
Orange-red
Density
4.81
Cleavage
On (010)
Fracture
Uneven
Transparency
Opaque
Crystal system
Orthorhombic

Diagnostic features

## Identification Leningradite can be identified by its intense red color, characteristic orange-red streak, and occurrence as small, tabular crystals on volcanic scoria. Its specific formation environment – volcanic fumaroles – is also key. ## Distinguishing from Similar Minerals It can be confused with other red secondary minerals found in similar environments, such as some arsenates or vanadates (e.g., vanadinite). Differentiation often requires advanced analytical methods, but the specific locality (Kamchatka volcanoes) and crystal habit are strong diagnostic indicators. ## Crystal Forms Leningradite crystals are usually very small, with a tabular or platy habit. They crystallize in the orthorhombic system. They occur as single, scattered crystals or small, loose aggregates on the surface of the host rock.

Geological environment

## Genesis Leningradite is a mineral of volcanic origin, formed by sublimation from volcanic gases (exhalations) at high temperatures. It crystallizes in fumaroles, where hot gases rich in vanadium, lead, copper, and chlorine react with volcanic rocks. ## Mineral Associations This mineral co-occurs with other rare volcanic exhalation products, such as hematite, tenorite, anglesite, ponomarevite, piipite, lammerite, urusovite, and other vanadates. ## Localities The only confirmed and type locality for leningradite is the Tolbachik volcanic field in Kamchatka, Russia, specifically from the products of the 1975-1976 eruption (Great Tolbachik Fissure Eruption).

Rarity

Very rare

For collectors

## Quality Criteria The most prized leningradite specimens are those with well-formed, sharp crystals of intense red color, clearly contrasting with the light background of the host rock. Due to the small size of the crystals, their number and good distribution on the matrix are crucial. Specimens with single crystals visible to the naked eye are rare. ## Popular Localities The only source of leningradite specimens is its type locality – Tolbachik volcano in Kamchatka. All specimens available on the collector's market come from this single location, making them particularly desirable for collectors specializing in minerals from specific localities (so-called "locality collectors") and rare species.

Care and storage

## Cleaning Leningradite specimens should be cleaned with the utmost care, using only compressed air to remove dust. Any contact with water, chemical solutions, and mechanical cleaning (e.g., brushes) should be avoided, as this could irreversibly damage the delicate crystals. ## What to Avoid The mineral is sensitive to moisture and chemicals. Avoid contact with water, acids, detergents, and sudden temperature changes. It should not be exposed to direct sunlight, which can cause changes in its structure or color. ## Storage Leningradite specimens should be stored in dry conditions, preferably in tightly sealed "perky box" containers, which protect against dust, moisture, and mechanical damage. Due to the fragility of the crystals, vibrations and shocks should be avoided.

External references

Sources

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