Aragonite
Aragonite is a carbonate mineral prized by collectors for its exceptional color range, with notable Chinese occurrences.
About Aragoniteextended article
Aragonite (CaCO₃) is the orthorhombic polymorph of calcium carbonate, distinct from calcite by its denser packing and pseudo-hexagonal twinning. It forms acicular sprays, “flos ferri” branching coral-like masses, and pseudo-hexagonal twins. Famous worldwide from Molina de Aragón (Spain — the type locality) and Erzberg (Austria).
Forms and colors
Aragonite's needle habit dominates our material: radiating white acicular sprays from Guizhou, sky-blue needle clusters and ribbed "goblet" forms from Yunnan, and the branching coral-like flos ferri from Austria's historic iron districts. The blue Yunnan material owes its color to trace copper — unusual for the species, which is most often white to cream.
Collector notes
At hardness 3.5–4 with brittle needles, aragonite is among the most fragile display minerals — dust with air, not cloth, and keep sprays where nothing can brush them. Chemically it is the same CaCO₃ as calcite; given geological time or heat it converts to its more stable cousin, which is why ancient aragonite is rare.
From our inventory
See Guizhou and Yunnan locality pages, or the calcite guide for the polymorph comparison.
About Aragonite
Aragonite belongs to the carbonate class in the aragonite group and has the chemical formula CaCO3. It crystallizes in the orthorhombic system and is one of the most visually varied minerals in the collector market.
Identification & care
Aragonite typically forms prismatic, tabular, acicular; characteristic pseudohexagonal 'trilling' twins; also botryoidal, coralline, cave sinter. Its color range is broad, including colorless to white or grey, often stained blue, green, red, and or violet by impurities. The luster is vitreous, resinous, the streak is white, uncolored, and specimens are typically transparent, translucent. The cleavage is distinct on {010}, imperfect on {110}. The fracture is sub-conchoidal, which aids identification.
Collector context
Collector notes
For collectors, Aragonite is a benchmark crystalline species. Documented Chinese occurrences are recorded at Bayan Obo deposit, among others.
Available Aragonite specimens
Flos Ferri Aragonite, Austria
Blue Aragonite Needle Cluster, Yunnan, China
Blue Aragonite Crystal Cluster – Sky Blue – Yunnan, China
Aragonite – Goblet Form – Ribbed Texture – Yunnan Province, China
