mineral

Banded calcite (possibly Iceland spar)

Calcite, CaCO₃

AI-generated identification · may be incorrect

Gray and white translucent bands with a vitreous-to-pearly luster and prominent cleavage; Mohs hardness 3, trigonal crystal structure, specific gravity about 2.7. The specimen’s appearance is consistent with calcite, though a photo cannot confirm the identification.

Identified October 15, 2026More mineral →

Explore Banded calcite (possibly Iceland spar) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Calcite forms in sedimentary rocks, veins, and caves through precipitation from calcium-rich water; banding records changing growth conditions. It forms across many geological ages.

Uses & applications

Used in cement and lime production, construction, and as a mineral specimen; clear optical calcite has specialized uses, but this piece appears suited mainly to collecting.

Geological facts

Calcite fizzes in dilute acid and is soft enough to scratch with a copper coin. Iceland spar is a transparent calcite variety famous for double refraction.

Field identification & locations

Look for easy rhombohedral cleavage, relatively low hardness, and acid effervescence; common worldwide in limestone, marble, and hydrothermal veins. The visible bands alone do not establish a precise locality or variety.