Reptile Jasper Identification Guide

What Reptile Jasper Looks Like

Reptile jasper (also marketed as snakeskin or crocodile jasper, and closely related to kambaba-type material) is an opaque microcrystalline quartz rock with a distinctive mottled, scaly pattern of dark green, olive, gray, and black, often in rounded orbs or net-like cells that resemble reptile skin. Luster is dull to waxy, it is fully opaque, and it takes a high polish. Many "kambaba/reptile" jaspers are actually silicified stromatolitic sediment, but they behave like jasper in the field.

Step-by-Step Field ID Checklist

1. Look at the pattern. Rounded green orbs/cells in a darker matrix, scale-like mottling.
2. Check opacity. Reptile jasper is opaque even on thin edges (unlike chalcedony/agate, which transmit light).
3. Test the luster. Dull when rough, waxy-to-glassy when polished.
4. Hardness check. Scratches glass; not nicked by a steel knife.
5. Inspect fracture. Smooth conchoidal chips.

Key Diagnostic Tests

• Mohs hardness: 6.5–7 (quartz family); scratches glass.
• Streak: White to pale (despite dark body color).
• Cleavage/fracture: None; conchoidal/smooth fracture.
• Density: ~2.6 g/cm³.
• Acid: No reaction (separates it from any carbonate-rich green stone).
• Magnetism: None (helps separate from green chlorite/serpentinite rocks with magnetite).

Common Look-Alikes and How to Tell Them Apart

• Kambaba jasper: Essentially the same family of green-black orbicular jasper; "reptile" is a pattern-based trade name. Both are hard quartz-rich rocks.
• Ocean jasper: Also orbicular, but brighter and more colorful (white, pink, yellow orbs); reptile jasper is dominated by green/black.
• Serpentinite / green nephrite: Softer feeling and often greasy; nephrite is extremely tough but ~6–6.5 and lacks the orb pattern. Serpentine is softer (~3–5) and can be scratched by a knife.
• Green moss agate: Translucent with dendritic inclusions in clear chalcedony; reptile jasper is opaque with solid green cells.
• Unakite: Pink-and-green granitic rock with visible feldspar/epidote crystals, not a smooth orbicular jasper.

Where Reptile Jasper Is Found

Green orbicular "reptile/kambaba" jaspers come largely from Madagascar and South Africa, with similar silicified microbial/sedimentary deposits elsewhere. Look for it as polished slabs, tumbles, and rough nodules; in the field it weathers out of silica-rich sedimentary and metasedimentary sequences.

Formation and Collecting Notes

Most green-black "reptile/kambaba" jasper is silicified microbial sediment (stromatolitic material) in which fine silica replaced and cemented layered algal/sedimentary structures, producing the rounded orbs and net-like cells that read as reptile scales. The green tones come from iron- and chlorite-rich phases locked in the silica.

In the field or at a show, confirm it behaves like jasper: hard enough to scratch glass, opaque on a thin edge, white-streaked, and inert to acid. The acid test is worth doing because some green ornamental rocks (serpentinite, carbonate-veined stones) are softer or carbonate-bearing and will give themselves away. A strong magnet is a quick screen against magnetite-bearing green metamorphic rocks. Because the name is purely descriptive, do not over-trust labels — "reptile," "crocodile," "snakeskin," and "kambaba" jaspers overlap heavily and all key out as hard opaque orbicular silica rock. Specimens take a brilliant polish, and the most prized pieces show crisp, well-separated green eyes against a near-black matrix.