Magselite
Chemical formula: [Mg(H₂O)₆](Se⁴⁺O₃)
Magselite is a hydrated magnesium selenite, forming colorless, acicular crystals, occurring as an evaporation product in arid climates.
Properties
- Mohs hardness
- 2.5-0
- Color
- colorless
- Luster
- Vitreous
- Streak
- white
- Density
- 2.10
- Cleavage
- Perfect on {010}
- Fracture
- Conchoidal
- Transparency
- Transparent
- Crystal system
- Trigonal
Diagnostic features
## Identification Magselite can be identified by its characteristic form – it creates small, colorless, acicular crystals, often in radial aggregates. A key diagnostic feature is its water solubility. It occurs in a specific environment – as efflorescences on sedimentary rocks in arid climates. ## Distinguishing from similar minerals It can be confused with other hydrated sulfates or selenites, such as epsomite or cobaltomenite. It differs from epsomite (Epsom salt) in its genesis and environment of occurrence. It is distinguished from cobaltomenite by its lack of color – cobaltomenite is pink or red due to the presence of cobalt. Final differentiation requires chemical analysis. ## Crystal forms Crystals are elongated, acicular or fibrous (acicular habit). They usually form radial or chaotic aggregates, as well as thin coatings and crusts on the surface of the host rock.
Geological environment
## Genesis Magselite is a secondary mineral, formed by the evaporation of waters rich in selenium and magnesium. It forms as an efflorescence on the surface of sedimentary rocks, such as sandstones, under desert or semi-desert conditions. Its formation is associated with the weathering of primary selenium minerals. ## Mineral associations This mineral co-occurs with other selenites and sulfates formed under similar conditions. It is most often accompanied by cobaltomenite, chalcomenite, as well as native selenium and baryte. ## Localities The most important and type locality for magselite is the Baggs area in Carbon County, Wyoming (USA), where it was discovered. This is the main locality from which specimens of this mineral originate.
Rarity
Very rare
For collectors
## Quality criteria The most valued magselite specimens are those that have rich, dense aggregates of well-formed, acicular crystals. The size of the crystals, their transparency, and their aesthetic arrangement on a small fragment of the host rock are important. Contrast with darker rock enhances the visual appeal of the specimen. ## Popular localities The only significant source of collector's specimens of magselite is its type locality – the Baggs area in Wyoming, USA. Specimens from this location are the standard for this mineral.
Care and storage
## Cleaning The mineral is water-soluble, so wet cleaning is absolutely forbidden. To remove dust, a very soft brush or a stream of compressed air from a safe distance can be used very carefully. ## What to avoid Avoid contact with water and any moisture, which can cause it to dissolve. Protect it from high temperatures, which can lead to dehydration and destruction of the crystals. Avoid all chemicals and ultrasonic cleaning. ## Storage Magselite specimens must be stored in a dry environment. It is best to place them in a sealed, airtight container (a "perky box") with a desiccant, such as silica gel. Protect it from shocks and mechanical damage due to its brittleness.