Sidorenkite
Chemical formula: Na<sub>3</sub>Mn<sup>2+</sup>(PO<sub>4</sub>)(CO<sub>3</sub>)
Sidorenkite is a rare mineral from the carbonate-phosphate group, forming small, pink or yellowish-brown crystals and aggregates.
Properties
- Mohs hardness
- 3
- Luster
- Vitreous
- Streak
- White
- Density
- 3.2
- Cleavage
- Perfect on {001}
- Fracture
- Uneven
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Sidorenkite can be identified by its characteristic pink or yellowish color, tabular crystal habit often forming rosette-like aggregates, and occurrence in a specific geological environment – alkaline pegmatites. A key diagnostic feature is its violent reaction (effervescence) upon contact with dilute hydrochloric acid. ## Distinguishing from Similar Minerals It can be confused with other pink minerals from alkaline pegmatites, such as eudialyte or serandite. It differs from eudialyte by its lower hardness and violent reaction with acid. It differs from serandite by its crystal habit (serandite forms elongated prisms) and perfect cleavage. ## Crystal Forms Crystals are most often tabular, flattened parallel to {001}, with a hexagonal or rhombic outline. They frequently occur as radial, rosette-like, or spherulitic aggregates. Prismatic crystals are less common.
Geological environment
## Genesis Sidorenkite is a hydrothermal mineral, crystallizing in the late stages of the evolution of highly differentiated alkaline massifs. It forms in vugs and fissures within nepheline-syenite pegmatites. ## Mineral Associations This mineral co-occurs with other rare alkaline minerals. In the Lovozero Massif (Russia), these include aegirine, natrolite, microcline, nepheline, ussingite, serandite, vuonnemite, zirsinalite, and chkalovite. In the Mont Saint-Hilaire complex (Canada), it is associated with aegirine, albite, microcline, natrolite, serandite, eudialyte, and leucophanite. ## Localities The most important and classic localities for this mineral are the alkaline massifs on the Kola Peninsula in Russia (Lovozero and Khibiny), where it was discovered. The second significant occurrence, providing high-quality specimens, is the Poudrette quarry at Mont Saint-Hilaire in Quebec, Canada.
Rarity
Very rare
For collectors
## Quality Criteria The most prized specimens by collectors are those with well-formed, sharp crystals of intense, pink color. Aesthetic, rosette-like aggregates are also highly valued, especially those contrasting with a light rock matrix. Crystal clarity and absence of mechanical damage are important. Specimens from Mont Saint-Hilaire are generally considered superior in terms of crystal quality and size compared to those from the Kola Peninsula. ## Popular Localities Undoubtedly, the most sought-after specimens come from the Poudrette quarry at Mont Saint-Hilaire (Quebec, Canada). Specimens from the type locality in the Lovozero Massif (Russia) are primarily of historical and scientific significance, less frequently forming aesthetic collector-grade pieces.
Care and storage
## Cleaning Sidorenkite specimens should be cleaned very carefully, using a soft brush to remove dust. Due to its reactivity with acids, contact with water should be limited to a minimum, and if necessary, distilled water should be used, and the specimen dried immediately. ## What to Avoid The mineral is sensitive to acids, in which it reacts violently, releasing carbon dioxide. Contact with chemicals, ultrasonic cleaners, and sudden temperature changes should be avoided. Prolonged exposure to strong light may cause some pink specimens to fade. ## Storage It is recommended to store specimens under stable conditions, in closed boxes or display cases, away from sources of moisture, direct sunlight, and chemical contaminants. Due to its brittleness, it should be avoided to place it in contact with harder minerals.