Camérolaite
Chemical formula: Cu²⁺₆Al₃(OH)₁₈(H₂O)₂[Sb⁵⁺(OH)₆](S⁶⁺O₄)
Camérolaite is a rare mineral from the cyanotrichite group, a hydrated copper and aluminum sulfate with antimony, forming blue-green, acicular crystals.
Properties
- Luster
- Vitreous
- Streak
- light green
- Density
- 3.1
- Cleavage
- {100} and {001}
- Fracture
- Fibrous
- Transparency
- Transparent
- Crystal system
- Triclinic
Diagnostic features
## Identification Identification of camérolaite is based on its characteristic mode of occurrence – tiny, acicular crystals forming radial aggregates or crusts. Key features include its blue-green color and co-occurrence with other secondary copper and arsenic minerals in the oxidation zones of deposits. Identification typically requires stereoscopic magnification. ## Distinguishing from Similar Minerals Camérolaite can be confused with other minerals from the cyanotrichite group, such as cyanotrichite or carbonatecyanotrichite. Cyanotrichite usually has a more intensely blue color. Final differentiation from these minerals requires advanced chemical (EDS) or X-ray (XRD) analyses to confirm the presence of antimony and sulfates. ## Crystal Forms The mineral forms very small, elongated, acicular or bladed crystals. Most often, they occur as radial or stellate aggregates, as well as tangled, felt-like masses covering the host rock.
Geological environment
## Genesis Camérolaite is a secondary mineral, forming in the oxidation zones (gossans) of polymetallic ore deposits rich in copper, arsenic, and antimony. It forms as a result of the weathering of primary sulfides, mainly chalcopyrite and tetrahedrite, in the presence of aluminum derived from clay rocks or feldspars. ## Mineral Associations This mineral co-occurs with other rare secondary minerals. In its type locality (Cap Garonne), it was found in association with, among others, olivenite, brochantite, and other minerals from the cyanotrichite group. It occurs on Triassic sandstones. ## Localities The most important and typical locality is the Cap Garonne mine in Le Pradet, near Toulon, France, which is known for the occurrence of many rare secondary minerals. Beyond France, its presence has been noted in several other places worldwide, including the Clara mine in the Black Forest (Germany) and mines in the Atacama region (Chile).
Rarity
Very rare
For collectors
## Quality Criteria The quality of camérolaite specimens is primarily assessed based on the richness and aesthetics of the crystal aggregates. The most valued specimens are those with well-formed, radial rosettes of intense, blue-green color, clearly contrasting with the host rock. The size of the crystals, although always small, is also important – the larger the needles, the more valuable the specimen. Association with other rare minerals is also significant. ## Popular Localities By far the most known and valued specimens come from the type locality – the Cap Garonne mine in France. Material from this location is considered exemplary for this mineral species.
Care and storage
## Cleaning Specimens should be cleaned very carefully, preferably using compressed air to remove dust. Any contact with water or chemicals is inadvisable. Due to the extreme delicacy of the crystals, mechanical cleaning (e.g., with a brush) is out of the question, as it leads to irreversible damage to the specimen. ## What to Avoid Avoid contact with water, acids, detergents, and all chemical agents. The mineral is sensitive to shocks, impacts, and abrasion. It should not be heated or exposed to prolonged strong light. ## Storage Camérolaite specimens, as microminerals, should be stored exclusively in specialized, sealed "micromount" boxes that protect them from dust, moisture, and mechanical damage. Touching the crystals should be avoided.