Arsenatrotitanite

Chemical formula: NaTi₄+(As₅+O₄)O

Arsenatrotitanite is a rare sodium titanium arsenate, forming small, prismatic crystals with a vitreous luster.

## Characteristics Arsenatrotitanite is a very rare mineral from the arsenate group. It occurs as very small, prismatic or acicular crystals, rarely exceeding 0.2 mm in length. The crystals are transparent to translucent and characterized by a vitreous luster. Due to its extreme rarity and small crystal size, it is a mineral known primarily in scientific circles and specialized micromineral collections. ## Physical Properties Arsenatrotitanite crystals exhibit a hardness of approximately 5 on the Mohs scale. They have a vitreous luster and are transparent to translucent. The mineral's density has been calculated at 4.13 g/cm³. ## Colors and Varieties This mineral is colorless or has a pale yellow hue. No varieties have been distinguished. ## History and Name Arsenatrotitanite was discovered in fumaroles of the Tolbachik volcano in Kamchatka, Russia. Its name, approved by the IMA in 2013 (IMA2013-010), refers to its chemical composition – the presence of arsenate (Arsenat-), titanium (-titan-), and sodium (-natro-, from Latin *natrium*). It was described by a team of mineralogists led by Igor V. Pekov. ## Uses Arsenatrotitanite has no industrial applications. Its significance is purely scientific and collectible, as a unique and rare mineral species.

Properties

Mohs hardness: 5
Luster: Vitreous
Streak: White
Density: 4.13
Cleavage: Perfect on {100}
Fracture: Uneven
Transparency: Transparent to Translucent
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of arsenatrotitanite is possible almost exclusively using advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS/WDS) with an electron microprobe. Visual identification in the field is impossible due to the microscopic size of the crystals and their resemblance to many other fumarolic minerals. ## Distinguishing from Similar Minerals It can be confused with other colorless or pale yellow minerals found in the same environment, such as arseniopleite, niobokupletskite, or other rare arsenates. Certain distinction requires specialized laboratory equipment. ## Crystal Forms Arsenatrotitanite forms elongated, prismatic to acicular crystals, often gathered in small, radial aggregates or chaotically arranged groups on the surface of the host rock.

Geological environment

## Genesis It is a mineral of volcanic origin, formed by exhalation (sublimation from hot volcanic gases) in active fumaroles. It crystallizes at temperatures above 450°C in an environment rich in arsenic, titanium, and sodium. ## Mineral Associations Arsenatrotitanite co-occurs with other fumarolic minerals such as hematite, tenorite, aphthitalite, johillerite, arseniopleite, svabite, niobokupletskite, and baddeleyite. ## Localities The only confirmed locality of arsenatrotitanite in the world is its type locality – the Arsenatnaya fumarole on the second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption (1975-1976) on Tolbachik volcano, Kamchatka, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of arsenatrotitanite specimens is primarily assessed based on the abundance and development of microscopic crystals. Most valued are specimens with numerous, well-formed, transparent crystals forming visually attractive groups on a small fragment of host rock. Due to their microscopic nature, the clarity and size of individual crystals are less important than the overall aesthetics of the aggregate under high magnification. ## Popular Localities The only source of specimens is the Tolbachik volcano in Kamchatka. Material from this locality is extremely rare and sought after by collectors specializing in systematic minerals and microminerals.

Care and storage

## Cleaning Specimens of this mineral are extremely small and fragile, so mechanical or chemical cleaning is not recommended. Any attempts at cleaning may destroy the crystals. It is safest to leave the specimen undisturbed. ## What to Avoid Avoid contact with any chemicals, ultrasonics, and sudden temperature changes. The crystals are very susceptible to mechanical damage. ## Storage Arsenatrotitanite specimens should be stored exclusively in specialized "micromount" boxes, which protect them from dust, shocks, and damage. Avoid exposing them to direct sunlight, although there is no evidence of fading.

Sources

IMA Mineral List (CNMNC)