Swamboite-(Nd)

Chemical formula: Nd<sub>0.333</sub>[(U<sup>6+</sup>O<sub>2</sub>)(SiO<sub>3</sub>OH)](H<sub>2</sub>O)<sub>~2.5</sub>

Swamboite-(Nd) is an extremely rare uranyl mineral, distinguished by its intense yellow color and the presence of neodymium in its structure.

## Characteristics Swamboite-(Nd) is a hydrated uranyl neodymium silicate. It forms microscopic, acicular or bladed crystals of an intense yellow color, which usually occur as radial aggregates or coatings on other uranium minerals. Due to their size, individual crystals are most often observable only under magnification. ## Physical Properties The crystals exhibit a luster described as silky or dull in the case of compact aggregates. The mineral is highly radioactive due to its high uranium content. It is soft and brittle. Precise values for hardness and density have not been accurately determined due to the small size of the crystals. ## Colors and Varieties This mineral occurs in a characteristic bright yellow to canary yellow color. No color varieties or commercial names are known. ## History and Name The mineral's name comes from its discovery locality in the Swambo mine in the Shaba region (now Katanga) in the Democratic Republic of Congo. It was described in 2011 by Travis A. Olds and co-workers. The suffix "-(Nd)" indicates the dominant rare earth element in its composition – neodymium.

Properties

Mohs hardness
2
Luster
Silky
Streak
Light yellow
Density
3.96
Cleavage
Perfect on {100}
Fracture
Uneven
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Key diagnostic features include its intense yellow color, acicular crystal habit forming radial aggregates, and occurrence in the oxidation zones of uranium deposits. The most important feature is strong radioactivity, easily detectable with a Geiger counter. Final identification requires advanced analytical methods, such as EDS spectroscopy, to confirm the presence of uranium, silicon, and neodymium. ## Distinguishing from Similar Minerals Swamboite-(Nd) can be confused with many other yellow secondary uranium minerals, such as uranophane, kasolite, or sklodowskite. Uranophane often forms similar radial aggregates, but Swamboite-(Nd) is distinguished by the presence of neodymium in its chemical composition, which cannot be determined without specialized analysis. ## Crystal Forms The mineral forms very fine, acicular or bladed crystals that combine into radial, stellate, or fibrous aggregates. Less commonly, it occurs as thin coatings and efflorescences.

Geological environment

## Genesis Swamboite-(Nd) is a secondary mineral, forming in the oxidation (weathering) zones of hydrothermal uranium deposits. It forms as a result of the alteration of primary uranium minerals, such as uraninite, in the presence of solutions rich in silica and rare earth elements. ## Mineral Associations It most commonly co-occurs with other secondary uranium minerals, such as uranophane, soddyite, kasolite, sklodowskite, and bijvoetite-(Y). The primary mineral in its environment is usually uraninite. ## Localities The only confirmed locality for this mineral worldwide is its type locality – the Swambo mine, located west of Shinkolobwe in Katanga Province, Democratic Republic of Congo.

Rarity

Extremely rare

For collectors

## Quality Criteria Due to its extreme rarity and microscopic crystal size, every analytically confirmed specimen is extremely valuable. Samples where Swamboite-(Nd) aggregates are clearly visible, well-formed, and contrast with the matrix are most highly prized. Association with other rare uranium minerals is also important. ## Popular Localities The only source of specimens is the Swambo mine in the Democratic Republic of Congo, making it a classic and highly sought-after locality for collectors specializing in rare and radioactive minerals.

Care and storage

## Cleaning Specimens should not be wet cleaned. Only gentle dust removal with a soft brush or compressed air from a safe distance is permissible. ## What to Avoid Contact with water, chemicals, and ultrasound should be strictly avoided. The mineral is sensitive to changes in temperature and humidity. As a uranium mineral, it is highly radioactive and requires special precautions. Direct skin contact, inhalation of dust, and storage in areas of permanent human presence should be avoided. ## Storage Specimens should be stored in sealed, lead-lined or glass containers away from other radiation-sensitive minerals. The container must be clearly labeled as radioactive material. Store in a dry place, away from heat sources and direct sunlight.

Sources

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