Novgorodovaite

Chemical formula: Ca<sub>2</sub>((C<sub>2</sub>)<sup>6+</sup>O<sub>4</sub>)Cl<sub>2</sub>·2H<sub>2</sub>O

Novgorodovaite is a very rare, colorless or white organic mineral, which is a hydrated calcium oxalate and chloride.

## Characteristics Novgorodovaite is a mineral from the oxalate group, chemically a hydrated calcium oxalate and chloride. It occurs extremely rarely, forming small, tabular or prismatic crystals that can form rosette aggregates. It is usually colorless to white and has a vitreous luster. Due to its rarity and small crystal size, it is primarily an object of scientific interest. ## Physical Properties Novgorodovaite crystals are soft, with a Mohs hardness of approximately 2.5. The mineral is characterized by a vitreous luster and is transparent to translucent. It has perfect cleavage in one direction. ## Colors and Varieties Novgorodovaite is usually colorless or white. No color varieties or commercial varieties are distinguished. ## History and Name The mineral was named after Margarita Novgorodova (born 1929), a Russian mineralogist and crystallographer, director of the A.E. Fersman Mineralogical Museum in Moscow. It was discovered and described in 1998. ## Uses Novgorodovaite has no industrial applications. It is solely a mineral of scientific and collecting importance, sought after by specialists due to its extreme rarity.

Properties

Mohs hardness
2.5
Luster
Vitreous
Streak
White
Density
2.16
Cleavage
Perfect on {001}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Identifying novgorodovaite in the field is practically impossible due to its appearance and rarity. Identification requires advanced laboratory methods, such as X-ray diffraction (XRD) and chemical analysis (EDS/WDS). In a collection, it can be recognized by its characteristic, small, tabular crystals and perfect cleavage. ## Distinguishing from Similar Minerals It can be confused with other colorless, secondary minerals, such as gypsum or other rare chlorides and oxalates. Differentiation with the naked eye is unfeasible; chemical analysis confirming the presence of calcium, chlorine, and the oxalate group is necessary. ## Crystal Forms It forms thin, tabular crystals with a pseudohexagonal habit, as well as short prismatic crystals. Crystals often occur as rosette-like or radial aggregates.

Geological environment

## Genesis Novgorodovaite is a secondary mineral, formed by the reaction of chloride-rich solutions with surrounding rock minerals, under specific, dry conditions. At its discovery site (Korshunovskoye mine), it likely formed from the reaction of formation waters with whewellite within basalt-gabbro intrusions. ## Mineral Associations This mineral co-occurs with whewellite, calcite, quartz, magnetite, hematite, pyrite, apatite, chlorite, and clay minerals. ## Localities The only confirmed locality of novgorodovaite in the world is the Korshunovskoye iron ore mine, located near the city of Zheleznogorsk-Ilimsky in the Irkutsk Oblast, Siberia, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria Due to its extreme rarity, every novgorodovaite specimen is valuable. Samples with well-formed crystals visible to the naked eye or rich aggregates on the matrix rock are most highly prized. The aesthetic composition and lack of damage to delicate crystals are also important. ## Popular Localities The only source of specimens is the Korshunovskoye mine in Russia. Material from this locality is extremely difficult to obtain and appears on the market very sporadically.

Care and storage

## Cleaning Due to its extreme rarity and delicacy, novgorodovaite specimens should not be cleaned mechanically or chemically. Any treatments should be performed exclusively by professional laboratories. If necessary, compressed air (from a safe distance) can be used to remove dust. ## What to Avoid Avoid contact with water, acids, bases, and all organic solvents. The mineral is soft and brittle, so it should be protected from impacts, scratches, and vibrations. Avoid changes in temperature and humidity. ## Storage Specimens should be stored in stable conditions, preferably in a closed, padded "micromount" box or capsule. They should be kept away from light, dust, and chemical contaminants.

Sources

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