Belovite-(La)
Chemical formula: NaLaSr<sub>3</sub>(PO<sub>4</sub>)<sub>3</sub>F
Belovite-(La) is a rare lanthanide and strontium phosphate, forming hexagonal, prismatic crystals with a characteristic honey-yellow color.
Description
## Characteristics Belovite-(La) is a mineral from the apatite group, belonging to the phosphate class. Its name indicates the dominance of lanthanum among rare earth elements in its structure. It forms well-developed, hexagonal, prismatic crystals, often with an elongated habit. Specimens typically have a characteristic luster, from vitreous to slightly greasy on crystal faces. ## Physical Properties The hardness of belovite-(La) on the Mohs scale is 5, making it a mineral of moderate scratch resistance. It is relatively brittle. Its density is approximately 4.19 g/cm³, making it noticeably heavier than most common rock-forming minerals. It exhibits weak, indistinct cleavage. ## Colors and Varieties The most common color is honey-yellow to yellowish-green. Colorless specimens are rarer. There is a close counterpart, belovite-(Ce), in which cerium is the dominant rare earth element. Distinguishing between the two minerals requires advanced chemical analysis. ## History and Name The mineral was first described in 1954 by L. S. Borodin and M. E. Kazakova. The name honors Nikolai Vasilyevich Belov (1891-1982), a prominent Russian crystallographer and geochemist who made significant contributions to the study of mineral structures. The suffix "-(La)" was added to distinguish it from the cerium-rich variety, in accordance with the rules for naming minerals with rare earth elements. ## Applications Belovite-(La) has no industrial applications. It is valued solely as a rare and visually attractive collector's mineral, as well as a subject of scientific research due to its complex structure and chemical composition.
Diagnostic features
## Identification Key diagnostic features include crystal form (hexagonal, elongated prisms), honey-yellow color, vitreous to greasy luster, and specific occurrence environment (alkaline pegmatites). Many specimens exhibit yellow fluorescence under ultraviolet (UV) light. ## Distinguishing from Similar Minerals Belovite-(La) can be confused with belovite-(Ce), from which it is visually indistinguishable without chemical analysis. Fluorapatite can also be similar, but it rarely exhibits a greasy luster and is much more common. Mimetite, although sometimes similar in color and form, is significantly denser. ## Crystal Forms It most commonly occurs as single, well-formed, long prismatic crystals with a hexagonal base. Granular or radial aggregates are rarer.
Geological environment
## Genesis Belovite-(La) is a hydrothermal mineral, crystallizing in the late stages of pegmatite formation within alkaline nepheline-syenite massifs (so-called agpaitic pegmatites). ## Mineral Associations It often co-occurs with other rare minerals typical of alkaline pegmatites, such as aegirine, nepheline, lamprophyllite, lorenzenite, eudialyte, sodalite, and fluorapatite. ## Localities The most important and well-known localities for belovite-(La) worldwide are in Russia, on the Kola Peninsula, within the Lovozero and Khibiny alkaline massifs. These are the places that provide practically all collector specimens of this mineral.
Rarity
Very rare
Collector aspects
## Quality Criteria Specimens with well-formed, sharp, and lustrous crystals of intense, honey-yellow color are most highly valued. Large, single crystals or aesthetic groups on a rock matrix are particularly sought after. The presence of rare associated minerals significantly increases the value of a specimen. ## Popular Localities The localities in the Lovozero massif (e.g., Mount Malyj Punkaruaiw, which is the type locality) and in the Khibiny Mountains on the Kola Peninsula in Russia are considered classic and provide the best specimens.
Care and storage
## Cleaning Specimens should be cleaned very carefully, using a soft brush and distilled water. Ultrasonic cleaners should be avoided, as they could damage the brittle crystals. ## What to Avoid The mineral is sensitive to acids, which can etch it. Due to its hardness of 5, it should be protected from contact with harder minerals (e.g., quartz, beryl) to avoid scratches. It is stable in sunlight and normal temperatures. ## Storage It is recommended to store specimens in separate, padded boxes or on soft stands to prevent abrasions and mechanical damage. It does not require special humidity conditions.