Moolooite
Chemical formula: Cu<sup>2+</sup>(C<sub>2</sub>)<sup>6+</sup>O<sub>4</sub>·nH<sub>2</sub>O
Moolooite is a very rare hydrated copper oxalate, forming characteristic blue or blue-green coatings and aggregates.
Properties
- Mohs hardness
- 3
- Luster
- Vitreous to Waxy
- Streak
- Pale blue
- Density
- 3.43
- Fracture
- Uneven
- Transparency
- Translucent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Characteristic features of moolooite include its blue to blue-green color, occurrence as earthy or powdery coatings, and low hardness. A key diagnostic clue is its formation environment – the presence of copper minerals in contact with organic matter (e.g., guano). ## Distinguishing from Similar Minerals Moolooite is sometimes confused with other secondary copper minerals, mainly chrysocolla. However, chrysocolla often has a lighter, whitish streak and may exhibit a conchoidal fracture. Unlike malachite and azurite, moolooite does not react with hydrochloric acid. Final confirmation of identity requires advanced analytical methods, such as X-ray diffraction (XRD). ## Crystal Forms Typical forms of occurrence are earthy, dusty, or powdery aggregates and coatings. Spherulitic or botryoidal aggregates, composed of microscopic tabular or bladed crystals, are rarely observed.
Geological environment
## Genesis Moolooite is a secondary mineral. It forms in the oxidation zone of copper ore deposits as a result of the reaction of copper-rich solutions with oxalic acid. The source of oxalic acid is decomposing organic matter, most often bird droppings (guano) or plant remains. ## Mineral Associations This mineral co-occurs with other secondary copper minerals, such as malachite, azurite, brochantite, atacamite, and gypsum. It is often accompanied by chalcopyrite (as a primary mineral) and quartz. At the type locality, its presence has been noted with other oxalates, e.g., whewellite. ## Localities The most important and well-known locality for moolooite worldwide is its type locality – Mooloo Downs Station in the Gascoyne region of Western Australia. This is the site from which most known specimens of this mineral originate.
Rarity
Very rare
For collectors
## Quality Criteria The main criterion for the collector's value of moolooite is its extreme rarity. Specimens are evaluated based on the intensity of color and the richness and coverage area on the host rock. Samples with visible spherulitic aggregates are particularly prized, although they are extremely rare. The presence of associated minerals can enhance the attractiveness of the specimen. ## Popular Localities The only commercially significant source of collector specimens is the type locality at Mooloo Downs Station in Australia. Specimens from this location serve as a benchmark for the quality and appearance of this mineral.
Care and storage
## Cleaning Moolooite specimens are very delicate and sensitive. To remove dust, use only a soft brush or a stream of compressed air from a safe distance. Avoid contact with water, which can affect its structure by changing its hydration state. ## What to Avoid This mineral is sensitive to heat and direct sunlight, which can lead to dehydration and color change. Absolutely avoid all chemicals, especially acids. It is soft, so it must be protected from scratches and abrasions. ## Storage It is recommended to store specimens in stable conditions, away from sources of heat, moisture, and light. The best solution is a closed, padded display box, which protects against dust and mechanical damage.