Daqingshanite-(Ce)
Chemical formula: Sr<sub>3</sub>Ce<sup>3+</sup>PO<sub>4</sub>(CO<sub>3</sub>)<sub>3</sub>
Daqingshanite-(Ce) is a rare strontium and cerium mineral from the phosphate and carbonate group, forming small, hexagonal crystals with a vitreous luster.
Description
## Characteristics Daqingshanite-(Ce) is a complex phosphate and carbonate of strontium and cerium. It most commonly occurs as small, well-formed, hexagonal crystals with a platy or short prismatic habit. Crystals rarely exceed a few millimeters in size. It also forms granular and massive aggregates, embedded in rock. It is a brittle mineral. ## Physical Properties The Mohs hardness of daqingshanite-(Ce) ranges from 4.5 to 5, placing it among minerals of medium hardness. Its density is relatively high, approximately 4.45 g/cm³. It is characterized by a vitreous, and on some surfaces, slightly greasy luster. It is transparent to translucent. ## Colors and Varieties This mineral is usually colorless, white, pale yellow, or greenish. No color varieties or commercial varieties are distinguished. ## History and Name The mineral's name comes from its discovery locality – the Daqingshan Mountains in the Inner Mongolia Autonomous Region, China. It was first described in 1983 by Ren Yingxin, Ximen Lüle, and Peng Zhizhong, and subsequently approved by the International Mineralogical Association (IMA). The suffix "-(Ce)" indicates the dominance of cerium in the chemical composition at a specific site in the crystal structure. ## Applications Daqingshanite-(Ce) has no industrial applications. Due to its rarity and small crystal size, it is solely an object of scientific interest and is valued by specialized collectors of rare minerals.
Diagnostic features
## Identification Identification of daqingshanite-(Ce) is based on its characteristic crystallographic form (short, hexagonal prisms), relatively high density, and specific occurrence environment (carbonatites rich in rare earth elements). It reacts with hydrochloric acid, which is a diagnostic feature for carbonates, however, this is a destructive test. Definitive identification requires advanced analytical methods such as X-ray diffraction (XRD) and chemical microanalysis (EDS). ## Distinguishing from Similar Minerals Daqingshanite-(Ce) can be confused with other minerals from the REE-carbonate or phosphate group that co-occur in the same environment, e.g., cebaite-(Ce), cordylite-(Ce), or some apatites. Distinguishing it based on visual characteristics is very difficult and usually requires laboratory analysis. It differs from them in density, hardness, and exact chemical composition. ## Crystal Forms It forms short, hexagonal prismatic and tabular crystals, often terminated by a pyramid. It also occurs as granular aggregates or as irregular grains embedded in the host rock.
Geological environment
## Genesis Daqingshanite-(Ce) is a mineral of hydrothermal origin. It forms in carbonatites, which are igneous carbonate rocks enriched in rare earth elements, strontium, and barium. ## Mineral Associations It most commonly co-occurs with minerals such as: benstonite, huntite, barite, fluorite, aegirine, riebeckite, phlogopite, dolomite, and calcite. ## Localities The most important and classic locality for daqingshanite-(Ce) is the Bayan Obo rare earth element deposit in Inner Mongolia (China). This is its type locality. Outside of China, its presence has been reported in a few places worldwide, including the Kola Peninsula in Russia, but specimens from these localities are extremely rare.
Rarity
Very rare
Collector aspects
## Quality Criteria The most highly prized daqingshanite-(Ce) specimens are those that contain well-formed, sharp, and transparent crystals with distinct color. Crystals embedded on a contrasting rock matrix, often accompanied by other rare minerals, are particularly sought after. Due to its small size, it is primarily a mineral for collectors specializing in micromounts. ## Popular Localities The only commercial source of collector specimens is the Bayan Obo deposit in China. This is the classic and most well-known locality, from which virtually all available material on the market originates.
Care and storage
## Cleaning Specimens should be cleaned very carefully, using a soft brush and distilled water. Due to its medium hardness, strong rubbing should be avoided. Ultrasonic cleaners are not recommended, as they could damage the brittle crystals. ## What to Avoid As a carbonate, daqingshanite-(Ce) is sensitive to acids, with which it reacts violently. Contact with any chemicals should be avoided. It is also recommended to protect specimens from prolonged exposure to direct sunlight and extreme temperature changes. ## Storage It is best to store specimens in separate, sealed display boxes to protect them from dust, moisture, and mechanical damage. A label with the name and locality is crucial for preserving its collector's value.