Vaterite

Vaterite crystals
from Mindat Vaterite

Description

A rare crystalline form of calcium carbonate that is composed of at least two different coexisting crystallographic structures. The major form exhibits hexagonal symmetry, while the minor form occurs within the nanodomains of the major matrix. Vaterite can occur as a biomineral in fish often formed by the dehydration of amorphous calcium carbonate.

Synonyms and Related Terms

vaterite (Port.); Vaterit (Deut.)

Physical and Chemical Properties

• Composition = CaCO3
• Color = Colorless
• Streak = White
• Mohs Hardness = 3
• Density = 2.54 g/ml
• Refractive Index = 1.550, 1.650
• Birefringence = 0.10
• Hexagonal crystal system
• Morphology = Thin fibers, spherulitic aggregates
• Reacts with acids to evolve carbon dioxide

Resources and Citations

• Wikipedia: Vaterite Accessed March 2025
• Mindat: Vaterite Accessed April 2024
• R. Gettens, E. West Fitzhugh, R.Feller, "Calcium Carbonate Whites", Artists Pigments, Vol. 2., A. Roy ed. Oxford University Press, Oxford, 1993.
• Mineralogy Database: Vaterite