George-ericksenite

Chemical formula: Na₆CaMg(I₅+O₃)₆(Cr₆+O₄)₂·₁₂H₂O

George-ericksenite is a rare, hydrated sodium, calcium, and magnesium iodate and chromate, forming pale yellow, transparent crystals.

## Characteristics George-ericksenite is a complex, hydrated mineral from the iodate and chromate group, with a complicated chemical composition including sodium, calcium, and magnesium. It occurs as small, tabular or bladed crystals, rarely exceeding 1 mm in length. These crystals are typically transparent and pale yellow, while in aggregates they adopt a more intense, lemon-yellow color. ## Physical Properties The mineral is characterized by a hardness of 3-4 on the Mohs scale, making it relatively soft. It has a vitreous luster. It is transparent. Due to its extreme rarity and small crystal size, its density has not been precisely measured. ## Colors and Varieties George-ericksenite occurs in a characteristic range of yellow colors. Individual crystals are pale yellow, and their aggregates have a vivid, lemon-yellow hue. No varieties of this mineral have been distinguished. ## History and Name The mineral was named in honor of George E. Ericksen (1920-1996), an American geologist with the U.S. Geological Survey, who was a prominent specialist in the geology and mineral deposits of Chile, including saltpeter. It was approved as a new mineral species by the International Mineralogical Association (IMA) in 2006. ## Uses Due to its extreme rarity and microscopic size, george-ericksenite has no industrial applications. Its significance is purely scientific and collectible, as a unique representative of complex iodates.

Properties

Mohs hardness: 3-4
Luster: Vitreous
Streak: Pale yellow
Density: 0
Transparency: Transparent
Crystal system: Monoclinic

Diagnostic features

## Identification Key diagnostic features include the intense, lemon-yellow color of aggregates, vitreous luster, and occurrence in a specific geological environment – in saltpeter deposits in Chile. Water solubility is also an important identifying characteristic. However, final confirmation requires advanced analytical methods, such as X-ray diffraction (XRD). ## Differentiation from Similar Minerals It can be confused with other yellow secondary minerals found in the same environment, such as other iodates. Distinguishing it based on visual characteristics alone is practically impossible and requires specialized research equipment. ## Crystal Forms It forms very small, tabular or bladed crystals, usually grouped into radial or randomly oriented aggregates. Single, well-formed crystals are extremely rare.

Geological environment

## Genesis George-ericksenite is a secondary mineral, forming in extremely arid, desert conditions. It forms as a product of weathering on the surfaces of nitrate deposits (Chilean saltpeter) in the northern Atacama Desert in Chile. ## Mineral Associations This mineral occurs in association with other rare minerals typical of saltpeter deposits, such as nitratine, halite, iodoargyrite, and other iodates and chromates. ## Localities The only confirmed locality of george-ericksenite in the world is its type locality: Oficina Chacabuco in Antofagasta Province, Chile. This is an abandoned saltpeter mine, known for the occurrence of many unique minerals.

Rarity

Extremely rare

For collectors

## Quality Criteria The most desirable specimens are those with visible, even if microscopic, crystals of an intense, lemon-yellow color, embedded in a contrasting rock matrix. Due to its extreme rarity, any authentic specimen, even in the form of a micro-aggregate, is considered valuable. ## Popular Localities The only source of specimens is the historic Oficina Chacabuco mine in Chile. Material from this locality is extremely difficult to acquire and appears on the collector's market sporadically.

Care and storage

## Cleaning Specimens should be handled with the utmost care. Cleaning should be kept to an absolute minimum. If necessary, compressed air can be used to remove dust. Contact with water should be avoided, as the mineral is soluble in it. ## What to Avoid Contact with water and all liquids, including cleaning agents, must be strictly avoided. The mineral is sensitive to moisture and can be damaged or dissolved. It should also be protected from high temperatures and direct sunlight, which can cause its degradation. ## Storage George-ericksenite specimens must be stored in a dry environment. It is best to place them in a sealed, lockable "perky box" away from sources of moisture. Due to its softness and fragility, vibrations and contact with harder minerals should be avoided.