mineral

Ocean Jasper

Spherulitic Chalcedony (SiO2)

Hardness: 6.5–7 Mohs; Color: Teal, green, yellow, and brown with orbicular patterns; Luster: Waxy to vitreous when polished; Crystal Structure: Hexagonal (Trigonal); Cleavage: None; Specific Gravity: 2.6–2.7

Hardness: 6
Color: Teal, green, yellow, and brown with orbicular patterns
Luster: Waxy to vitreous when polished

Identified April 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed as a result of rhythmic crystallization of silica-rich solutions in hydrothermal veins and volcanic cavities. This specific variety is found in Cretaceous volcanic rocks (approximately 66–112 million years old).

Uses & applications

Primarily used as a lapidary material for jewelry, palm stones, carvings, and as a highly sought-after collector's specimen due to its unique appearance.

Geological facts

Ocean Jasper is technically a misnomer; it is more closely related to chalcedony than true jasper. It is famously found only on the coast of Madagascar and can sometimes only be mined at low tide.

Field identification & locations

Identify by its distinctive 'orbicular' patterns (small circles or eyes) and vibrant multi-colored swirls. It is found in the Marovato area of Madagascar; look for its high silica hardness and lack of cleavage.