Natroxalate

Chemical formula: Na₂(C₂)⁶⁺O₄

Natroxalate is a rare, organic sodium mineral, forming small, colorless or pale yellow crystals with a vitreous luster.

## Characteristics Natroxalate is a hydrated sodium oxalate, belonging to a rare group of organic minerals. It occurs as small, tabular or prismatic crystals, often forming radial aggregates or granular masses. Individual crystals rarely exceed a few millimeters in length. It is a brittle mineral, with a characteristic vitreous luster on crystal faces. ## Physical Properties This mineral is relatively soft, with a Mohs hardness of 3. It is light, with a density of 2.32 g/cm³. It exhibits perfect cleavage in one direction and distinct cleavage in two others, resulting in a stepped fracture. It is transparent. ## Colors and Varieties Natroxalate is typically colorless, pale yellow, sometimes with a delicate pink or greenish tint. Fine-grained aggregates take on a creamy color. No varieties are distinguished. ## History and Name The mineral's name refers to its chemical composition – the presence of sodium (Latin: *natrium*) and the oxalate group. It was first described in 1996 by A.P. Khomyakov and colleagues based on material found in the Lovozero Massif in Russia. ## Applications Natroxalate has no industrial applications. It is solely an object of interest for collectors specializing in rare minerals and scientists studying unusual mineral-forming processes.

Properties

Mohs hardness
3
Luster
Vitreous
Streak
White
Density
2.32
Cleavage
perfect {100} and distinct {001} and {221} cleavages
Fracture
Step-Like
Transparency
Transparent
Crystal system
Monoclinic

Diagnostic features

## Identification Natroxalate can be identified by its occurrence in agpaitic pegmatites, low hardness (3 on the Mohs scale), vitreous luster, and characteristic small crystals, often forming radial aggregates. It reacts with acids, which is a diagnostic feature for oxalates. ## Distinguishing from similar minerals It can be confused with other colorless or pale yellow minerals found in similar environments, such as Natrite or Thermonatrite. It is distinguished from them by its crystal habit, perfect cleavage, and reaction with acids, which for oxalates is different from that for carbonates. ## Crystal forms It forms small, tabular or short-prismatic crystals. It is most commonly found in radial or stellate aggregates, as well as fine-grained, creamy masses filling small voids in the rock.

Geological environment

## Genesis Natroxalate is a hydrothermal mineral, crystallizing in the late stage of evolution of highly alkaline pegmatites (so-called agpaitic pegmatites). It forms in cavities and fissures as a result of the interaction of solutions rich in sodium and organic compounds with previously crystallized minerals. ## Mineral associations This mineral coexists with other rare alkaline minerals such as Ussingite, Natrosilite, Lomonosovite, Villiaumite, Sphalerite, as well as Natrite and Thermonatrite. ## Localities The most important and type locality for Natroxalate is Mount Alluaiv in the Lovozero Massif on the Kola Peninsula in Russia. This is practically the only locality from which well-formed, collector-quality specimens of this mineral originate.

Rarity

Very rare

For collectors

## Quality criteria The most valued specimens by collectors are those with well-formed, sharp, and transparent crystals, forming aesthetic, radial aggregates on a contrasting rock matrix. Crystal size is a key factor – specimens with crystals exceeding a few millimeters are exceptionally rare and sought after. The intensity of color and lack of damage are also important. ## Popular localities The only source of valuable collector specimens is the Lovozero Massif in Russia, particularly Mount Alluaiv. Specimens from this locality set the standard for this mineral.

Care and storage

## Cleaning Natroxalate specimens should be cleaned very carefully, using only a soft brush to remove dust. Due to its potential solubility in water, contact with liquids, especially acids, should be avoided. ## What to avoid Contact with water, chemical agents, and ultrasound must be strictly avoided. The mineral is soft and brittle, susceptible to scratches and mechanical damage. It should be protected from high temperatures and humidity. ## Storage It is recommended to store specimens in a dry place, preferably in a closed, padded collector's box, to protect them from dust, moisture, and mechanical damage. It should be isolated from harder minerals.

External references

Sources

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