Digital TownsCrystalsShop crystals
  1. Crystals & Minerals
  2. Kambaba Jasper

Kambaba Jasper: What the Green Orb Stone Really Is

By Digital Towns Crystals · Last reviewed October 8, 2026

Short answer: kambaba jasper, also sold as crocodile jasper, is a dark green rock from Madagascar with black round "eyes." It is widely marketed as fossilized stromatolite algae, but thin-section and microprobe analysis by the German gem lab EPI found a volcanic rock, a rhyolite of quartz and alkali feldspar with radiating amphibole clusters rimmed by aegirine. No jasper and no fossil structure was detected. It is a handsome, durable decorative stone; the fossil story is unsupported.

Is kambaba jasper a fossil stromatolite?

Not according to the only laboratory analysis available. The claim deserves to be laid out first, because nearly every product listing repeats it.

Stromatolites are real and important fossils: layered mounds built by colonies of cyanobacteria. The University of California Museum of Paleontology notes that cyanobacteria are the oldest known fossils, more than 3.5 billion years old, and that their photosynthesis generated much of Earth's oxygen atmosphere during the Archaean and Proterozoic. A stone that preserved such colonies would be remarkable, and the round, layered-looking orbs in kambaba make the comparison tempting. That is where the "over 3 billion years old" lines on many labels come from.

The story was tested in the mid-2000s. According to the Institut für Edelstein Prüfung (EPI), in 2005 the supplier of a similar Mexican rock circulated a notice saying its material was volcanic, while kambaba was "allegedly" a sedimentary rock, a fossil stromatolite also called "stromatolite jasper." EPI was then commissioned to examine kambaba. Working from a hand specimen of several kilograms from the original Madagascar site, the lab ran thin-section and microprobe analyses, and reported that the rock is clearly not sedimentary.

What EPI found instead:

  • Groundmass: quartz and alkali feldspars (albite and sanidine, or a related phase).
  • The dark orbs: radially arranged green amphibole aggregates (pargasite, riebeckite or related phases), mantled by fine-grained pyroxene, aegirine.
  • Calcite: only in traces, which EPI says clearly refutes the claim that kambaba is a sedimentary rock formed from stromatolite algae.
  • Texture: amphibole in minute needles with flow structure in places, indicating crystallization from viscous magma.

EPI's conclusion is that the rock is a volcanic rock, more precisely a rhyolite, and that the fine intergrowth probably developed as a former melt devitrified. The lab adds a fair caveat: a single hand specimen does not allow precise statements about the full deposit. That is the honest state of evidence. One lab analysis says volcanic; no published analysis we could find shows fossil structure.

If not fossils, what makes the round orbs?

Radiating needle growth. In EPI's description each dark cluster is a spray of tiny amphibole needles growing outward from a center, with aegirine forming a fine rim. Seen in cross section on a polished face, a ball of radiating needles reads as a dark circle with a lighter halo, which is exactly the "eye" collectors like. Stromatolites form a different way. The UCMP's cyanobacteria fossil record page explains that their layers were produced as calcium carbonate precipitated over growing mats of bacterial filaments, with sediment grains trapped in the sticky mucilage and the colony growing upward layer after layer. A cut stromatolite therefore shows stacked carbonate layers, not isolated dark spheres floating in a silicate groundmass, and EPI found calcite only in traces.

Rhyolite itself is a volcanic rock with very high silica. Geology.com describes it as an extrusive igneous rock with grains so small they are hard to see without a hand lens, usually made of quartz, plagioclase and sanidine with minor hornblende and biotite. High-silica magma is very viscous, which fits the flow textures EPI saw. Kambaba's dark tones fit its minerals: Minerals.net lists aegirine as black, brown, dark green or reddish black, and riebeckite as dark blue, dark green, gray or black, very different from the pink or gray of an ordinary rhyolite.

Why is it called jasper if it is not jasper?

Because trade names stick. Minerals.net defines jasper as an opaque variety of chalcedony, that is, fine-grained silica (SiO2), at Mohs 6.5 to 7 with a specific gravity of 2.63 to 2.65. EPI states plainly that "Cambamba Jasper" and "Crocodile Jasper" are misleading names, since jasper could not be detected in any of the samples it examined. Kambaba is closer to a speckled volcanic rock with some quartz in it than to a silica stone.

That puts kambaba in the same family as other "jaspers" that are not jasper, a pattern covered in the jasper trade names guide. It also sets it apart from ocean jasper, which Minerals.net lists as a genuine form of orbicular jasper with small, tight concentric rings, found on the coast of Madagascar. Same island, different rock.

What is the difference between kambaba, nebula stone and eldarite?

EPI compared kambaba with "Nebula Stone" from Mexico. A 1995 analysis by Sidney A. Williams, cited by EPI, described the Mexican rock as an alkali-rich volcanic rock of quartz, anorthoclase feldspar, riebeckite and aegirine, classified as quartz-pantellerite, which is an alkali-rich rhyolite. The two rocks differ mainly in proportions and pattern:

Name Origin Look Rock type (EPI)
Kambaba ("Kabamba Stone") Madagascar Black circles on a green background Rhyolite
Nebula Stone Mexico Green circles on a nearly black background Quartz-pantellerite (alkali-rich rhyolite)
Eldarite Either Umbrella name EPI accepts it for both

EPI notes that for decades the three names were used as synonyms, and that "Kabamba Stone" is the usual German trade name. Given how similar the mineralogy is, the lab considers "Eldarite" an acceptable general term for both.

How do you recognize kambaba jasper?

  • Pattern: round to oval black or very dark green orbs set in a mid to dark green groundmass. Some pieces show flowing, swirled zones between orbs.
  • Rough: EPI describes the rough as having a crusty surface similar to bulbous lava strands.
  • Polish: takes a good polish; the orbs and matrix usually polish evenly, with occasional softer patches.
  • Not ocean jasper: ocean jasper's orbs have pastel concentric rings and often druzy pockets; kambaba's are solid dark centers.

Under a 10x loupe, EPI's photos show fine, tightly intergrown minerals, and at 40x the dark areas resolve into green amphibole needles overgrown with aegirine. A loupe will not show cell structure or laminations, because there are none.

Is kambaba jasper safe to handle?

Polished pieces are a solid, coherent rock and are handled every day. One background fact is worth knowing for anyone who cuts stone: Minerals.net's riebeckite page explains that riebeckite's fibrous variety, crocidolite, is "blue asbestos." EPI's analysis describes the amphibole in kambaba as minute needles locked in the rock, and does not report fibrous asbestos, but lapidaries should cut, grind and sand any amphibole-bearing rock wet, as good practice for silica dust anyway. Finished spheres, towers and tumbles carry no dust when left alone.

Is kambaba associated with anything in crystal traditions?

In crystal traditions kambaba is associated with grounding, calm and a sense of deep time, an idea borrowed from the stromatolite story. Treat the age claim on labels as marketing; the tradition stands or falls on its own.

Choosing kambaba jasper

Kambaba is inexpensive by the pound, so price differences mostly reflect size, shape and how attractive the orb pattern is.

  1. Pattern density: well-defined orbs spread across the face are worth more than muddy, patchy green.
  2. Contrast: crisp black eyes with a lighter halo photograph and display best.
  3. Polish: look for an even shine across orbs and groundmass; dull pits mark softer spots or poor finishing.
  4. Labels: a listing that calls it a 3-billion-year-old fossil is repeating a claim a lab analysis did not support. That does not make the stone any less attractive, but it is a signal about how carefully the seller checks facts.
  5. Form: spheres and eggs show the orbs from every angle; flat-faced pyramids and towers show sectioned orbs as clean circles. The spheres guide covers what makes a good polished sphere.

Digital Towns Market

Kambaba jasper in stock

See all crystals and minerals

Frequently asked questions

Is kambaba jasper a real fossil?

The evidence says no. A thin-section and microprobe study of Madagascar kambaba by the German lab EPI found a volcanic rhyolite with amphibole and aegirine clusters and only traces of calcite, which refutes the sedimentary stromatolite claim. No published analysis has shown fossil structure in it.

Is kambaba the same as crocodile jasper?

Yes, both names are used for the same green Madagascar rock with dark orbs. Neither is mineralogically accurate: EPI could not detect jasper in any sample and calls the jasper names misleading. "Eldarite" is the general name the lab accepts.

What is the difference between kambaba and nebula stone?

They are closely related volcanic rocks. Kambaba from Madagascar shows black circles on a green background; Nebula Stone from Mexico shows green circles on a nearly black background. Both contain quartz, alkali feldspar, amphibole and aegirine.

How old is kambaba jasper?

No source we found gives a measured age for the Madagascar rock. The common "over 3 billion years" figure comes from the stromatolite story, borrowing the age of the oldest cyanobacteria fossils. Since the rock tested as volcanic, that number should not be relied on.

How do you care for kambaba jasper?

Wipe it with a damp cloth and dry it. It takes and holds a good polish and does not need special storage beyond keeping spheres on a stand so they cannot roll. If you cut or sand rough material, work it wet to keep dust down.

Sources