Stibioclaudetite
Chemical formula: As³⁺Sb³⁺O₃
Stibioclaudetite is a rare arsenic and antimony oxide, forming colorless to white, tabular crystals with a pearly or vitreous luster.
Properties
- Mohs hardness
- 2
- Color
- Colorless
- Luster
- Pearly, Vitreous
- Streak
- White
- Density
- 0
- Cleavage
- On {010}.
- Fracture
- Uneven
- Transparency
- Transparent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Stibioclaudetite is difficult to identify visually due to the small size of its crystals. Its characteristic tabular or bladed habit, pearly luster on cleavage surfaces, and occurrence in paragenesis with other rare arsenates and oxides are distinctive. Certain identification requires advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS). ## Distinguishing from Similar Minerals It can be confused with claudetite, which has a very similar appearance and properties but does not contain antimony. Distinguishing these two minerals without chemical analysis is practically impossible. Other similar secondary minerals, such as gypsum or mica, differ in hardness and genesis. ## Crystal Forms Stibioclaudetite crystals are monoclinic, with a habit of thin, flattened tablets or blades. They often form fan-shaped, radial, or chaotically arranged aggregates on the surface of the host rock.
Geological environment
## Genesis Stibioclaudetite is a secondary mineral, formed in the oxidation zones of ore deposits in hydrothermal environments. It forms as a result of the weathering of primary arsenic and antimony-bearing minerals under low temperature and pressure conditions. It occurs as coatings and aggregates on gangue rocks or in vugs. ## Mineral Associations This mineral co-occurs with other secondary arsenic and antimony minerals. At the type locality, it was found in association with native arsenic, arsenolite, claudetite, scorodite, pharmacosiderite, gypsum, and iron oxides. ## Localities The only confirmed and thoroughly described occurrence of stibioclaudetite in the world is its type locality – the waste dumps of the former uranium and silver mine Svornost in Jáchymov (Krušné Hory, Czech Republic).
Rarity
Extremely rare
For collectors
## Quality Criteria As a "micromount" type mineral of scientific value, its primary quality criterion is the abundance and good development of crystals on the rock matrix. Specimens with clearly visible, sharp, undamaged crystals forming aesthetic aggregates are most prized. Crystal size, even if not exceeding 1 mm, is crucial. Association with other rare minerals is also important. ## Popular Localities The only source of collector specimens is the Svornost mine in Jáchymov, Czech Republic. Specimens from this locality are highly sought after by collectors specializing in rare and systematic minerals.
Care and storage
## Cleaning Stibioclaudetite specimens are extremely delicate and small, so they should be cleaned with the utmost care. It is recommended to use compressed air (from a safe distance) to remove dust. Any mechanical contact, including with a soft brush, can destroy the fragile crystals. Wet cleaning is not recommended. ## What to Avoid Avoid contact with water and chemicals. The crystals are very soft and brittle, susceptible to mechanical damage from the slightest touch. They should be protected from vibrations and sudden temperature changes. ## Storage It is recommended to store specimens exclusively in sealed, padded "micromount" boxes to protect them from dust, moisture, and physical damage. Display should be in enclosed showcases.