Nixonite

Chemical formula: Na₂Ti⁴⁺₆O₁₃

Nixonite is an extremely rare sodium and titanium oxide mineral, discovered in the Murun alkaline complex in Siberia.

## Characteristics Nixonite is an oxide group mineral, chemically classified as a sodium titanate. It forms very small, elongated, lath-like crystals, reaching sizes up to 20x150 micrometers. It typically occurs as aggregates or inclusions within other minerals, mainly in potassium feldspar. It is colorless and transparent, with a strong, adamantine luster. ## Physical Properties Due to the microscopic size of the crystals, most physical properties, such as hardness, density, cleavage, or fracture, have not been precisely determined. The luster is described as adamantine, and the mineral is transparent. ## History and Name The mineral was approved by the International Mineralogical Association (IMA) in 2018 under the number IMA2018-089. The name honors Forrest F. Nixon II (born 1955), an American mineral collector from Texas, in recognition of his contribution to the preservation of rare mineral specimens. It was discovered by a Russian team of mineralogists in material originating from the Murun massif in Russia.

Properties

Mohs hardness: 5-6
Luster: Adamantine
Streak: White
Density: 3.51
Cleavage: Perfect on {100}
Transparency: Transparent
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of nixonite is impossible without advanced analytical techniques, such as Raman spectroscopy and chemical analysis using an electron microprobe (EDS/WDS). Visually, under high magnification, colorless, lath-like crystals with adamantine luster, embedded in feldspar, can be observed. ## Distinction from similar minerals Distinguishing it from other microscopic, colorless oxide or silicate minerals (e.g., zircon, anatase) occurring in the same environment requires specialized analysis of chemical composition and crystal structure. ## Crystal forms Crystals are strongly elongated, lath-like or prismatic. They occur as single, isolated crystals or small, loose clusters of inclusions in potassium feldspar.

Geological environment

## Genesis Nixonite forms under unique geological conditions, in rocks rich in potassium and titanium, and poor in silica. It was identified in fenites – metasomatic rocks formed by the interaction of strongly alkaline fluids with surrounding rocks (in this case, sandstones) within an ultramafic magmatic complex. ## Mineral associations This mineral coexists with microcline (potassium feldspar), wadeite, dalyite, priderite, anatase, and titanium and niobium oxides. ## Localities The only confirmed occurrence of nixonite in the world (type locality) is the Murun massif in the Irkutsk Oblast, Siberia, Russia. This area is known for the occurrence of many other rare alkaline minerals.

Rarity

Extremely rare

For collectors

## Quality criteria As a microscopic mineral, nixonite is not evaluated by typical criteria such as size or color. The value of a specimen lies in its extreme rarity and confirmation of its identity through scientific analysis. The most valuable specimens are those where nixonite crystals are relatively "large" (over 100 micrometers) and clearly visible against the feldspar matrix. The presence of other rare associated minerals (e.g., wadeite) increases its scientific and collector value. ## Popular localities The only source of specimens is the Murun massif in Russia. Research and collector material comes exclusively from this single locality.

Care and storage

## Cleaning Due to its extreme rarity and the microscopic size of crystals embedded in another mineral (matrix), cleaning is neither recommended nor possible without specialized laboratory equipment. Any attempt at cleaning risks irreversible damage or loss of the specimen. ## What to avoid Avoid all chemicals, ultrasonics, temperature changes, and any mechanical manipulations. The specimen should be treated solely as a research object or a unique collection item. ## Storage Store in stable conditions, in a specialized "micromount" box, protecting it from dust, vibrations, and direct light. It is best to keep it in the original container in which it was acquired.