mineral

Aragonite (Botryoidal/Coralloidal variety)

Aragonite (CaCO3)

Hardness: 3.5-4 (Mohs scale), Color: White to cream or light brown, Luster: Vitreous to dull, Crystal Structure: Orthorhombic (often forming as botryoidal or cave popcorn-like masses), Cleavage: Distinct/Poor in one direction, Specific Gravity: 2.9-3.0.

Hardness: 3

Identified April 6, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through precipitation from calcium-rich waters in caves, hot springs, or marine environments. This specific bubbly form is often called 'Flos Ferri' or 'Cave Popcorn' and is typically found in the oxidation zones of ore deposits or within limestone caverns.

Uses & applications

Primarily used as a mineral specimen for collectors and as a decorative stone. Large deposits can be used as a source of calcium for cement or agricultural lime.

Geological facts

Aragonite is a polymorph of Calcite, meaning they share the same chemistry (Calcium Carbonate) but different crystal structures. It is a major component of sea shells and pearls. Over time, aragonite often recrystallizes into the more stable calcite.

Field identification & locations

Identify in the field by its effervescence (bubbling) when exposed to weak acids like vinegar. Look for its characteristic 'bubbly' or branching 'coral-like' structure in limestone areas. It is denser and harder than calcite.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral