Bluebellite
Chemical formula: Cu<sup>2+</sup><sub>6</sub>(I<sup>5+</sup>O<sub>3</sub>)(OH)<sub>10</sub>Cl
An extremely rare copper iodate of intense blue color, forming microscopic, tabular crystals.
Properties
- Mohs hardness
- 2
- Luster
- Vitreous to Pearly
- Streak
- Light blue
- Density
- 3.99
- Cleavage
- Perfect on {0001}
- Fracture
- Micaceous
- Transparency
- Translucent
- Crystal system
- Trigonal
Diagnostic features
## Identification Identification of bluebellite is based on its characteristic azure-blue color, its occurrence as microscopic, rosette-like aggregates composed of hexagonal tablets, and its extreme rarity. Definitive identification requires advanced analytical methods, such as Raman spectroscopy or X-ray diffraction (XRD), due to its co-occurrence with other blue secondary minerals. ## Distinguishing from Similar Minerals Bluebellite can be confused with other blue secondary copper minerals, such as linarite, azurite, cyanotrichite, or to some extent, shattuckite. Distinguishing it with the naked eye or under a loupe is practically impossible. The key is to examine the crystal morphology under high magnification – bluebellite forms characteristic, thin hexagonal plates. Linarite often has more elongated crystals, and azurite forms different crystal habits and is acid-sensitive. ## Crystal Forms Crystals are very thin, tabular, with a hexagonal or pseudohexagonal outline. They usually occur as rosette-like, spherulitic, or irregular aggregates, as well as thin coatings.
Geological environment
## Genesis Bluebellite is a secondary mineral formed in the oxidation zones (gossans) of polymetallic deposits. It forms under arid conditions as a result of the weathering of primary copper ores in the presence of iodine and chlorine. Iodine likely originates from groundwater or the decomposition of organic matter in a dry climate. ## Mineral Associations This mineral co-occurs with other rare secondary minerals. At the type locality (Blue Bell mine), it was found in association with, among others, boleite, pseudoboleite, anglesite, cerussite, chalcanthite, hemimorphite, linarite, as well as newly described minerals like marcasite and iodo-salesite. ## Localities The only confirmed and described occurrence of bluebellite in the world is its type locality – the Blue Bell mine, located in the Soda Mountains Mining District, Baker area, San Bernardino County, California, USA.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of bluebellite specimens is assessed almost exclusively based on the richness and aesthetics of the aggregates observed under a microscope. Samples with numerous, well-formed, rosette-like clusters of intense blue color, contrasting with the rock matrix, are most highly valued. The size of the aggregates, although always microscopic, is also important – larger rosettes are more desirable. The purity of the specimen refers to the absence of damage to the delicate crystals. ## Popular Localities The only source of bluebellite specimens is the Blue Bell mine in California. Material from this location is extremely rare and sought after by specialized micromineral collectors.
Care and storage
## Cleaning Bluebellite specimens are extremely delicate and consist of microscopic crystals. They should not be cleaned mechanically or chemically. Any attempt at cleaning, even with a soft brush or compressed air, risks irreversible damage to the fragile aggregates. ## What to Avoid Avoid contact with water, acids, bases, and all solvents. The mineral is likely sensitive to changes in temperature and humidity. It should not be heated or exposed to direct sunlight, which may cause dehydration or color change. ## Storage Specimens should be stored exclusively in specialized micromount boxes, which protect them from dust, shocks, and physical contact. Display is only possible under a microscope.