Madagascar Jasper Identification Guide
A field guide to identifying Madagascar (Ocean) Jasper by its orbicular spheres, hardness, and waxy chalcedony body.
Read the full Madagascar Jasper encyclopedia entry →
What Madagascar Jasper Looks Like
Madagascar Jasper most often refers to orbicular jasper — the famous "Ocean Jasper" type — a silica rock (jasper/chalcedony) studded with rounded orbs and rings. Some Madagascar jasper is also flowing polychrome jasper.
- Color: highly varied — green, yellow, white, red, pink, brown, gray, often multicolored
- Luster: dull to waxy on rough; glassy polish
- Transparency: opaque, with occasional translucent chalcedony orbs
- Texture: circular "eyes," orbs, and rings (orbicular), or swirling polychrome banding
Step-by-Step Field ID Checklist
- Look for orbs or rings — concentric circular patterns ("eyes") are the hallmark of the orbicular Madagascar/Ocean Jasper.
- Confirm opacity with bright light — the body is opaque, though tiny druzy quartz pockets may sparkle.
- Test hardness — scratches glass and steel (Mohs ~6.5-7).
- Look at fracture — conchoidal, sharp-edged, waxy.
- Check for druzy quartz cavities common in Ocean Jasper.
Key Diagnostic Tests
- Mohs hardness: 6.5-7.
- Streak: white.
- Cleavage: none; conchoidal fracture.
- Specific gravity: ~2.6.
- Acid: no reaction (separates from carbonate look-alikes).
Common Look-Alikes and How to Tell Them Apart
- Other orbicular jaspers (e.g., poppy jasper): distinguished mainly by color/locality; all are silica, so tests overlap. Madagascar Ocean Jasper is famed for sea-green/white orbs and druzy pockets.
- Agate: translucent and banded; Madagascar jasper is opaque.
- Carbonate "jasper" imitations: soft (Mohs 3) and fizz in acid.
- Dyed jasper/howlite: howlite is much softer (3.5) and chalky; dye concentrates in veins.
Where It Is Typically Found
This material comes from Madagascar — Ocean Jasper famously from coastal deposits near Marovato in the northwest, plus various polychrome jaspers from across the island.
Frequently asked questions
What is Madagascar Jasper?
Madagascar Jasper usually refers to orbicular Ocean Jasper from Madagascar — an opaque silica rock featuring circular orbs and rings in green, white, red, and yellow, often with druzy quartz pockets.
How can you tell if Madagascar Jasper is real?
It is opaque, Mohs 6.5-7 (scratches glass and steel), has a waxy-to-glassy luster and conchoidal fracture, and does not fizz in acid. Soft, acid-reactive stones are carbonate fakes.
Is Madagascar Jasper the same as Ocean Jasper?
Ocean Jasper is the most famous Madagascar jasper — an orbicular variety from coastal northwest Madagascar — but the island also produces flowing polychrome jaspers sold under the same regional name.
What does Madagascar Jasper look like?
It is opaque and multicolored, typically showing rounded orbs and concentric rings ('eyes') in greens, whites, reds, and yellows, sometimes with sparkling druzy quartz cavities.
Madagascar Jasper identified by the community
Recent Madagascar Jasper specimens identified with Rock Identifier.
