mineral and sedimentary

Larimar and Fossil Coral

Pectolite (NaCa2Si3O8(OH)) and Hexagonaria/Petoskey Stone

AI-generated identification · may be incorrect

Larimar: Hardness 4.5-5.0, Blue to white, Vitreous to silky luster, Triclinic. Fossil Coral: Hardness 3.5-4, Tan/Grey with coral pattern, waxy luster.

Identified April 2, 2026More mineral and sedimentary →

Explore Larimar and Fossil Coral in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Larimar: Hardness 4.5-5.0, Blue to white, Vitreous to silky luster, Triclinic. Fossil Coral: Hardness 3.5-4, Tan/Grey with coral pattern, waxy luster.

Formation & geological history

Larimar is a rare blue variety of pectolite found only in the Dominican Republic, formed in basaltic cavities during volcanic events. The fossil beads are petrified ancient coral, primarily from the Devonian period roughly 350-400 million years ago.

Uses & applications

Used primarily in high-end jewelry, lapidary arts, and as collector gemstones due to their aesthetic appeal and rarity.

Geological facts

Larimar is often called the 'Dolphin Stone' or 'Atlantis Stone' and is found in only one square kilometer in the entire world. The fossil beads show 'honeycomb' patterns indicative of ancient rugose corals.

Field identification & locations

Identify Larimar by its unique marbled blue-and-white color and localized Caribbean origin. Identify fossil coral by the distinctive geometric 'star' or honeycomb patterns on the surface of the stones.