mineral

Polished ocean jasper / orbicular jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque, glassy-to-waxy luster when polished, with reddish-brown, mustard-yellow, cream, and green mottling. It has no visible cleavage and a cryptocrystalline quartz structure; specific gravity is approximately 2.5–2.7.

Identified August 10, 2026More mineral →

Explore Polished ocean jasper / orbicular jasper 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

Forms when silica-rich fluids fill cavities or replace volcanic rock, with iron and other impurities producing the colors and patterns. Most ocean jasper originates in Oligocene–Miocene volcanic rocks of Madagascar, roughly 5–30 million years old.

Uses & applications

Used for cabochons, beads, carvings, polished stones, and decorative objects; attractive patterned pieces are popular with collectors.

Geological facts

“Ocean jasper” is a trade name, not a single mineral species; orbicular patterns may resemble eyes or cellular growth rings.

Field identification & locations

Identify it by its very fine-grained, opaque chalcedony body, hardness, and natural multicolor orbicular or brecciated patterns; glass scratches more easily. Common sources include Madagascar, Mexico, Australia, and Indonesia.