“Jasper”… technically a misnomer

Despite the name, Kambaba is not a jasper (microcrystalline quartz with impurities). It’s a rhyolitic volcanic rock whose orbicular patterns come from crystal growth, not sedimentary banding. Lab work by EPI (Germany) identified quartz + albite + sanidine with amphiboles (riebeckite/pargasite) and aegirine; no stromatolite fabric was found. :contentReference[oaicite:2]{index=2}

Trade names, same stone

You’ll see Kabamba (local spelling), Crocodile jasper (for the eye‑spots), and in some literature both Kambaba and Mexican Nebula Stone grouped under the umbrella “Eldarite.” Mineralogically, both are volcanic rocks with similar minerals—Kambaba tends to show black circles on green; Nebula Stone flips that to green circles on black. :contentReference[oaicite:3]{index=3}

From melt to pattern

Kambaba begins as felsic lava. As it cools, glassy parts devitrify—tiny crystals of quartz and feldspar grow, while amphiboles nucleate as radial sprays. These spherulitic clusters become the familiar dark orbs with green haloes. :contentReference[oaicite:5]{index=5}

Why it fooled people

At a glance, the orbs resemble stromatolites (layered structures made by cyanobacteria). But stromatolites show laminated, sedimentary textures; Kambaba’s orbs are crystalline and igneous. Analytical work and thin sections support the volcanic origin. (Verdict: lava did it.) :contentReference[oaicite:6]{index=6}

Devitrification drama

Under magnification, the dark spots resolve into minute amphibole needles overgrown by aegirine—a textbook result of viscous magma crystallizing in place after cooling. :contentReference[oaicite:7]{index=7}

Palette

• Forest/olive green groundmass (quartz + feldspar).
• Black orbs (amphibole‑rich cores), often with thin aegirine rims.
• Lime haloes—paler green reaction zones around orbs.

Good slabs show high contrast but with natural, slightly misty edges to the orbs—no stencil‑sharp rings.

Pattern words

• Orbicular “eyes” — rounded orbs, sometimes with two‑tone haloes.
• Vortices — curved streaks of green around clusters of orbs.
• Chain orbs — beads of spots strung along a subtle flow line.

Photo tip: Use raking light ~25–30°. A single, small source makes the haloes glow and the black “pupils” look deep—very crocodile chic.

Radial needles

At 10×, dark orbs resolve into fine amphibole needles radiating from the center; a thin, slightly brighter aegirine rim may outline the orb. :contentReference[oaicite:11]{index=11}

Groundmass

The green background shows a tight, fine mosaic of quartz + feldspar with scant glass left—classic devitrified texture. :contentReference[oaicite:12]{index=12}

Flow hints

In places, orb chains and wispy streaks hint at flow lines in viscous lava—watch for gentle curvature and alignment.

True stromatolites

Laminated, layered structures made by microbes in sedimentary settings. Under magnification they show fine laminae, not radial amphibole needles. Kambaba’s volcanic petrology and mineralogy rule out fossil origin. :contentReference[oaicite:13]{index=13}

Nebula Stone (Mexico)

Very similar mineral suite (quartz, alkali feldspar, amphibole, aegirine) but typically green orbs on black. Both are volcanic; some labs group them under “Eldarite.” :contentReference[oaicite:14]{index=14}

Rainforest rhyolite

Also an orbicular/spotted rhyolite, usually brighter pistachio/cream palettes with more brecciation. Harder to mistake once you’ve seen both side by side.

Green jaspers

Microcrystalline quartz varieties (true jaspers) can be mottled or orbicular, but lack the radial amphibole texture and igneous flow hints under a loupe.

Quick checklist

• Dark, rounded orbs with radial needles inside? → Kambaba.
• Laminated bands like tree‑rings? → Stromatolite, not Kambaba.
• Green orbs on black? → Likely Nebula Stone.

Name note

“Crocodile jasper” = Kambaba look. “Kabamba” is a common local spelling. “Jasper” persists in the trade, even though the rock is rhyolite. :contentReference[oaicite:15]{index=15}

Madagascar (classic)

The best‑known material comes from the Bongolava region in west‑central Madagascar; you’ll also see locality notes referencing “Kabamba.” :contentReference[oaicite:16]{index=16}

How it’s sold

Rough, slabs, palm stones, and cabochons are common. Patterns vary by lot—from tight “eye” fields to bold swirls with linked orbs.

Everyday care

• Clean with lukewarm water + mild soap; dry promptly.
• Avoid sharp blows and extreme hot/cold swaps.
• Store separately so the polish stays crisp (quartz dust is sneaky).

Jewelry guidance

• Cabochons & beads shine—dark orbs read well at small scale.
• For rings/bracelets, use protective bezels and mindful wear (Mohs ~6–7).
• Pairs well with brushed silver or matte black settings for contrast.

On the wheel

• Fresh belts, light pressure. If “orange peel” appears, slow down and refine the pre‑polish.
• Pre‑polish 600→1200→3k; finish with cerium or tin oxide on a firm but forgiving pad.
• Orient slabs so a few standout orbs sit off‑center—it feels more dynamic in a cab.

Loupe the “pupil”

Pick a dark orb and zoom in. You should see radial, hair‑fine needles from center to rim—your proof of igneous growth.

Flow finder

Gently rotate a slab under raking light; some orbs line up along faint curves—traces of lava motion frozen mid‑swirl.