Dmitryvarlamovite

Chemical formula: Ti⁴⁺₂(Fe³⁺Nb⁵⁺)O₈

Dmitryvarlamovite is a very rare, black oxide mineral from the columbite supergroup, discovered in Russia.

## Characteristics Dmitryvarlamovite is a very rare mineral from the columbite supergroup, composed of titanium, iron, and niobium. It occurs as very fine, black, tabular crystals, usually not exceeding 10 micrometers, forming irregular aggregates. Its appearance is inconspicuous, and identification requires advanced analytical methods. ## Physical Properties This mineral is characterized by a hardness of 6 on the Mohs scale and a density of 4.89 g/cm³. It exhibits a black streak and a conchoidal fracture. It is opaque and has a metallic luster. ## Colors and Varieties The only known color of dmitryvarlamovite is black. No varieties have been distinguished. ## History and Name The mineral is named in honor of Dmitry Ivanovich Varlamov (born 1976), a Russian geologist from the All-Russian Research Institute of Mineral Resources (VIMS) in Moscow, for his contribution to the study of bauxite deposits. The mineral was officially approved by the IMA in 2020, and its discovery was made in archival material from a drill core taken in 1984. ## Uses Due to its extreme rarity and microscopic size, dmitryvarlamovite has no industrial applications. It is of purely scientific significance and is of interest to specialized micromineral collectors.

Properties

Mohs hardness
6-0
Luster
Metallic
Streak
black
Density
4.891
Fracture
Conchoidal
Transparency
Opaque
Crystal system
Orthorhombic

Diagnostic features

## Identification Identification of dmitryvarlamovite is impossible without advanced analytical techniques, such as energy-dispersive X-ray spectroscopy (EDS) or electron diffraction. Visually, it is simply a black, metallic mineral of microscopic size. ## Distinguishing from Similar Minerals It can be confused with other black, opaque minerals from the columbite group, such as columbite-(Fe), columbite-(Mn), or ilmenite. Differentiation requires chemical composition analysis, especially the proportions of titanium, niobium, and iron. ## Crystal Forms It forms very small, tabular crystals up to 10 micrometers in size, which combine into irregular aggregates up to 50 micrometers.

Geological environment

## Genesis Dmitryvarlamovite forms under low-temperature hydrothermal conditions. At its type locality, it was found in calcite-dawsonite veins cutting bauxite sedimentary rocks. Its formation is associated with the metasomatic alteration of aluminum- and titanium-rich rocks. ## Mineral Associations It co-occurs with minerals such as calcite, dawsonite, nordstrandite, goethite, hematite, anatase, and rutile. ## Localities The only confirmed occurrence worldwide is its type locality – the Verkhne-Shugorskoe bauxite deposit within the Timan Ridge in the Komi Republic, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria As a micromineral, the value of a specimen is primarily determined by the abundance and size of dmitryvarlamovite aggregates within the host rock. Precise confirmation of its identity by analytical methods is also important. Due to its microscopic nature, visual aesthetics are of secondary importance. ## Popular Localities The only source of specimens is the type locality in Russia. The material originates from archival drill cores, making it extremely difficult to acquire.

Care and storage

## Cleaning Due to the microscopic size of the crystals and their embedding in the host rock, mechanical cleaning is neither recommended nor possible. Specimens should be protected from dust. ## What to Avoid Contact with strong acids and chemicals that could damage both the mineral itself and the surrounding rock should be avoided. Ultrasound and sudden temperature changes should also be avoided. ## Storage Dmitryvarlamovite specimens, as microminerals, should be stored in specialized "micromount" boxes, protecting them from dust, humidity, and mechanical damage.

External references

Sources

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