Novograblenovite

Chemical formula: (N₃-H₄)MgCl₃·₆H₂O

Novograblenovite is a rare, water-soluble magnesium ammonium chloride, forming colorless, acicular crystals on volcanic exhalation products.

## Characteristics Novograblenovite is a hydrated ammonium-magnesium chloride. This mineral forms colorless, transparent crystals with an acicular or hair-like habit, growing up to 1.5 mm long and about 0.01-0.02 mm thick. It occurs as tangled, woolly aggregates, as well as single, prismatic crystals. It is brittle and does not exhibit fluorescence under ultraviolet light. ## Physical Properties Novograblenovite crystals are characterized by a vitreous luster and a white streak. Its Mohs hardness is very low, at 1.5, meaning it is a very soft mineral. Its density is low, at 1.596 g/cm³. ## History and Name Novograblenovite was discovered on products of fumarolic activity at Tolbachik volcano in Kamchatka, Russia. It was approved as a new mineral species by the International Mineralogical Association (IMA) in 2018. The name honors Pyotr Tikhonovich Novograblenov (1892–1934), a Russian chemist and researcher of Kamchatka, who first described this chemical compound in nature in 1926, though without naming it. ## Uses Due to its rarity, small crystal size, and instability, novograblenovite is of scientific and collector interest only. It is valued by collectors specializing in volcanic minerals and rare species.

Properties

Mohs hardness: 1.5
Luster: Vitreous
Streak: White
Density: 1.596
Cleavage: None
Fracture: Uneven
Transparency: Transparent
Crystal system: Trigonal

Diagnostic features

## Identification The key diagnostic feature of novograblenovite is its mode of occurrence – delicate, acicular or hair-like crystals forming woolly aggregates. Its origin (volcanic exhalations) and extreme instability in humid environments are also characteristic. It reacts violently with water, dissolving. ## Distinguishing from Similar Minerals It can be confused with other soluble halides formed in fumaroles, such as salammoniac (NH₄Cl) or kremersite. Salammoniac usually forms more compact crusts or dendritic forms. Kremersite has a similar composition but crystallizes in a different system and is often colored yellow or red. Definitive distinction requires advanced analytical methods, such as X-ray diffraction (XRD). ## Crystal Forms Novograblenovite forms elongated, prismatic crystals with an acicular or hair-like habit. Crystals are often grouped into chaotic, tangled aggregates resembling mineral wool.

Geological environment

## Genesis Novograblenovite is a mineral of volcanic origin. It forms as a result of the sublimation of volcanic gases (exhalations) in active fumarole zones. It crystallizes at temperatures below 100°C directly from the gas phase on the surface of volcanic rocks, such as basalt. ## Mineral Associations This mineral co-occurs with other products of volcanic exhalations. At the discovery site (Tolbachik volcano), it was found in association with salammoniac, hematite, halite, sylvite, and the rare mineral cadwaladerite. ## Localities The only confirmed locality of novograblenovite in the world is its type locality: the fumarole field on the second cinder cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption (1975-1976) at Tolbachik volcano, Kamchatka, Russia.

Rarity

Very rare

For collectors

## Quality Criteria The quality of novograblenovite specimens is assessed based on the abundance and preservation of delicate, acicular crystals. The most desirable are rich, "fluffy" aggregates with a clearly visible structure, free from contamination and mechanical damage. It is also important that the specimen is well protected from moisture, which indicates careful collection and storage. ## Popular Localities The only source of specimens of this mineral is Tolbachik volcano in Kamchatka. Collector material is extremely limited and comes exclusively from scientific expeditions to this single locality.

Care and storage

## Cleaning The mineral is extremely sensitive to water and moisture. It must absolutely not be cleaned with water or any liquids. Specimens should be protected from contact with ambient moisture. ## What to Avoid Avoid water, water vapor, and high air humidity (above 30-40%), which leads to rapid dissolution of the mineral. High temperatures, which can cause the loss of water from its crystal structure, should also be avoided. It is very soft and brittle, so any physical contact should be avoided. ## Storage Novograblenovite specimens must be stored in sealed, airtight containers, preferably with a desiccant (e.g., silica gel). They should be kept at stable, low humidity and room temperature, away from direct sunlight.

Sources

IMA Mineral List (CNMNC)