Papagoite
Chemical formula: CaCu<sup>2+</sup>AlSi<sub>2</sub>O<sub>6</sub>(OH)<sub>3</sub>
Papagoite is a rare copper, calcium, and aluminum silicate, valued for its intense blue color and occurrence as inclusions in rock crystal.
Properties
- Mohs hardness
- 5.5
- Luster
- Vitreous
- Streak
- Pale blue
- Density
- 3.25
- Cleavage
- Perfect on {001}
- Fracture
- Uneven
- Transparency
- Translucent to opaque
- Crystal system
- Monoclinic
Diagnostic features
## Identification The most important diagnostic feature of papagoite is its characteristic, intensely blue color. Its occurrence as microcrystalline aggregates, coatings, or inclusions in quartz is also very typical. Unlike other blue copper minerals, papagoite does not react (does not effervesce) in contact with hydrochloric acid. ## Distinguishing from Similar Minerals Papagoite is sometimes confused with other secondary blue copper minerals, such as shattuckite or planchéite. Distinguishing them based on visual characteristics is often impossible and requires advanced analytical methods, such as X-ray diffraction (XRD). In the case of inclusions in quartz, confusion with dumortierite is possible, but dumortierite usually forms acicular or fibrous inclusions, while papagoite forms more compact, "cloud-like" aggregates. ## Crystal Forms Well-formed crystals are extremely rare and reach small sizes, usually less than 1 mm. They take tabular or short-prismatic forms. Most commonly found are microcrystalline aggregates, radial aggregates, coatings, and inclusions in rock crystal.
Geological environment
## Genesis Papagoite is a secondary copper mineral, meaning it forms as a result of oxidation and weathering processes of primary copper ore deposits. It forms in the oxidation zones (iron caps) of porphyry deposits, where waters rich in silica and aluminum react with copper minerals in an alkaline environment. It can fill small fissures and cracks in the host rock. ## Mineral Associations This mineral often co-occurs with other minerals from the oxidation zone. Its most common associations include: quartz (in which it forms famous inclusions), aurichalcite, shattuckite, ajoite, barite, chrysocolla, and iron oxides (hematite, goethite). ## Localities The most important and historical locality is the New Cornelia mine in Ajo, Pima County, Arizona, USA, where the mineral was discovered. Other known localities in Arizona include the Christmas mine and the Blue Bell mine. The most prized collector's specimens in the form of inclusions in quartz come from the Messina mine (now Musina) in Limpopo Province, Republic of South Africa.
Rarity
Rare
For collectors
## Quality Criteria The most highly valued papagoite specimens are those in the form of distinct, well-colored inclusions in transparent and clear rock crystal. The more intense and deep the blue color of the "phantom" and the better the transparency and quality of the quartz itself, the more valuable the specimen. For specimens without quartz, rich, microcrystalline coatings of vibrant color on a small rock matrix are desirable. Well-formed, independent microcrystals, though small, are extremely rare and command very high prices. ## Popular Localities Specimens from the Messina (Musina) mine in South Africa are by far the most sought-after in the collector's market, having supplied almost all available papagoite in quartz specimens. Specimens from the type locality in Ajo (Arizona, USA) are also valued, especially for historical reasons, but rarely match the aesthetics of those from South Africa.
Care and storage
## Cleaning Papagoite specimens, especially those in quartz, should be cleaned very carefully. It is best to use a soft brush to remove dust. If necessary, the specimen can be rinsed with lukewarm distilled water, then thoroughly dried with a soft cloth or allowed to air dry. Avoid ultrasonic cleaners, which can damage delicate inclusions or the quartz itself. ## What to Avoid Avoid contact with acids and strong chemicals, which can react with the mineral and cause discoloration or damage. Papagoite is sensitive to high temperatures. Prolonged exposure to direct sunlight can lead to fading of its intense color, so it should be avoided. ## Storage Specimens, especially those with inclusions in quartz, are best stored in separate boxes or on a soft surface to prevent scratching. It is advisable to protect them from dust and direct sunlight by displaying them in closed display cases with LED lighting that does not emit heat or UV radiation.