Mikecoxite
Chemical formula: [C<sup>4-</sup>Hg<sup>2+</sup><sub>4</sub>]OCl<sub>2</sub>
Mikecoxite is an extremely rare mercury oxychloride-carbonate, forming microscopic, transparent crystals with an adamantine luster.
Properties
- Mohs hardness
- 2-3
- Luster
- Adamantine
- Streak
- White
- Density
- 8.35
- Cleavage
- Perfect on {010}
- Fracture
- Brittle
- Transparency
- Transparent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Field identification of mikecoxite is impossible. Identification requires specialized laboratory equipment, such as a scanning electron microscope with EDS analysis or X-ray diffraction. In a collection, under a microscope, characteristic features include microscopic, colorless crystals with an exceptionally strong, adamantine luster, occurring on the matrix rock from the McDermitt mine. ## Distinguishing from Similar Minerals Mikecoxite can be confused with other colorless secondary mercury minerals from the same locality, such as kleinite or corderite. Differentiation relies on chemical and crystallographic analysis. However, its adamantine luster is significantly stronger than that of most associated minerals. ## Crystal Forms The mineral forms very small, tabular crystals with hexagonal or octagonal cross-sections, as well as short prismatic crystals. It occurs as single, isolated crystals scattered on the matrix rock or in small vugs within rock cavities.
Geological environment
## Genesis Mikecoxite is a secondary mineral that forms as a result of weathering and oxidation of primary mercury ores under low-temperature conditions. It forms in the oxidation zone of a mercury deposit, in voids and fractures of highly mineralized volcanic rock (rhyolitic tuffs). ## Mineral Associations This mineral occurs in association with other rare secondary mercury minerals, such as corderite, cinnabar, kleinite, native mercury, as well as calcite and quartz. ## Localities The only known occurrence of mikecoxite in the world is its type locality – the McDermitt Mine (Cordero Mine) in the Opalite district, Humboldt County, Nevada, USA.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of mikecoxite specimens is assessed based on several criteria. The size and quality of the crystals are most important – the larger, better-formed, and more transparent they are, the more valuable the specimen. Specimens with numerous, well-dispersed crystals on a contrasting matrix are desirable. The presence of rare associated minerals, such as kleinite, also increases collectible value. Due to the microscopic nature of the mineral, its "photogenicity" under a microscope is crucial. ## Popular Localities The only source of specimens is the McDermitt Mine in Nevada, USA. This is the type locality, and all specimens available on the collector's market come from this single location.
Care and storage
## Cleaning Mikecoxite specimens, due to their microscopic size and fragility, should generally not be mechanically cleaned. If loose dust needs to be removed, a photographic air blower can be used carefully. Avoid contact with water and any chemicals. ## What to Avoid The mineral is sensitive to shocks and mechanical stress. Contact with acids and other chemical reagents must be strictly avoided. Due to its mercury content, heating, which could release toxic fumes, should be avoided. Minimizing light exposure is recommended, although its effect is not fully understood. ## Storage Specimens should be stored exclusively in dedicated, sealed "micromount" boxes to prevent physical damage and limit potential risks associated with mercury content. Store in stable conditions, away from heat sources, humidity, and direct sunlight. Always wash hands after handling the specimen.