Aragonite
Aragonite · Mineral Specimen
Crystal System
Orthorhombic; typically forms prismatic, acicular, or tabular crystals often twinned into pseudo-hexagonal prismatic clusters.
Mineral Group
Carbonates (Anhydrous Carbonates)
Chemical Formula
CaCO3
Formation Process
Sedimentary, low-temperature hydrothermal, and biogenic processes; formed in near-surface conditions from evaporating waters or biologic secretions at low temperatures and pressures.
About This Crystal
The specimen features a cluster of brownish-orange, translucent to transparent, tabular-to-prismatic crystals with a vitreous to resinous luster. The crystals display characteristic pseudo-hexagonal twinning habits radiating outwards from a central matrix coated with reddish-brown earthy iron oxide sediment.
Physical Characteristics
Color ranges from honey brown to reddish-orange due to iron impurities; white streak; distinct cleavage in one direction; subconchoidal to uneven fracture; specific gravity of approximately 2.93; brittle tenacity; typically non-magnetic; may exhibit weak yellowish or greenish fluorescence under ultraviolet light.
Optical Properties
Biaxial negative; refractive indices range from n_alpha = 1.530 to n_gamma = 1.686; strong birefringence (0.156); no significant pleochroism due to pale body color.
Hardness & Durability
Origin Region
Notable sources include Morocco, Spain (Molina de Aragón), Pakistan, and the United States; typically forms in low-temperature aqueous environments, oxidation zones of ore deposits, and evaporation basins.
Hardness & Durability
Mohs hardness of 3.5 to 4; poor to distinct cleavage makes it brittle and sensitive to sharp impacts; low durability, making it generally unsuitable for everyday jewelry wear.
Care & Maintenance
Clean gently with warm, soapy water and a soft cloth; avoid ultrasonic or steam cleaners, harsh acids, and prolonged exposure to direct sunlight; store separately to prevent scratching by harder minerals.
Rarity & Value
Common to uncommon depending on crystal quality and formation size; well-formed twinned clusters from classic localities command moderate collector value, and the mineral is rarely treated or enhanced.
Special Characteristics
Famous for its cyclic pseudo-hexagonal twinning that mimics hexagonal crystals despite its true orthorhombic system; thermoluminescence is sometimes observed.
Lore & History
Named after the region of Aragon in Spain where it was first discovered; historically used as a grounding stone in crystal healing practices, traditionally associated with the root chakra to promote inner peace, emotional stability, and environmental connection (noted as traditional belief, not scientific fact).