Martinite
Chemical formula: (Na,◻,Ca)₁₂Ca₄(Si,S⁶⁺,B)₁₄B₂O₃₈(OH,Cl)₂F₂(H₂O)₄
Martinite is a very rare mineral from the fedorite group, found as colorless, violet, or pinkish-violet platy crystals.
Properties
- Mohs hardness
- 4
- Luster
- Vitreous
- Streak
- White
- Density
- 0
- Cleavage
- On {001}.
- Fracture
- Irregular/Uneven
- Transparency
- Transparent
- Crystal system
- Triclinic
Diagnostic features
## Identification Amateur identification of martinite is practically impossible. It requires advanced analytical methods, such as X-ray diffraction (XRD) and chemical analysis (EDS/WDS). Preliminary identification based on appearance (small, platy crystals in rosettes) and location (Mont Saint-Hilaire) is highly uncertain. ## Distinguishing from Similar Minerals At the type locality (Mont Saint-Hilaire), many other rare minerals with a similar appearance occur, including other minerals from the fedorite group. Visual distinction from these without specialized equipment is not possible. ## Crystal Forms Martinite forms thin, tabular (platy) or lath-like crystals with a hexagonal outline. These crystals often combine into small, radial or rosette-like aggregates.
Geological environment
## Genesis Martinite is a hydrothermal mineral. It forms in the late stage of crystallization within sodalite and syenite xenoliths that have been altered by metasomatic processes. It occurs in vugs and fractures of these rocks in the Mont Saint-Hilaire alkaline complex. ## Mineral Associations This mineral coexists with many other rare minerals typical of this locality. The most common associations include: analcime, aegirine, microcline, nepheline, sodalite, eudialyte, stephanite, sérandite, as well as other minerals from the fedorite group. ## Localities The only confirmed occurrence of martinite in the world is its type locality - the Poudrette quarry at Mont Saint-Hilaire in Quebec, Canada. This is one of the most famous mineralogical sites in the world, known for the occurrence of hundreds of unique and rare mineral species.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of martinite specimens is primarily assessed based on the abundance and development of crystals. Specimens with clearly formed, radial aggregates or rosettes, set on a contrasting rock matrix, are most valued. The intensity of the violet color, though rare, also enhances the specimen's attractiveness. Due to their microscopic size, the aesthetics of the entire mineral assemblage, rather than a single crystal, are crucial. ## Popular Localities All known martinite specimens come from a single location worldwide: the Poudrette quarry at Mont Saint-Hilaire in Canada. Specimens from this locality are highly sought after by collectors specializing in rare minerals and systematic minerals.
Care and storage
## Cleaning Martinite specimens are extremely delicate and small. They should be cleaned only with great care, using compressed air to remove dust. Any contact with water, and especially with brushes, risks irreversible damage to the fragile crystals. ## What to Avoid Avoid contact with all chemicals, including acids and detergents. The mineral is sensitive to mechanical damage, so avoid vibrations, impacts, and abrasion. It should not be heated or subjected to ultrasound. ## Storage Martinite specimens should be stored in stable, sealed "micromount" containers that protect them from dust, moisture, and physical damage. Avoid exposure to direct sunlight, although there is no evidence of fading.