# Orbicular jasper

- Page: https://taslar.bumba.tr/en/stones/orbicular-jasper/
- Turkish: Orbiküler jasper
- Also known as: Ocean jasper (Madagascar), Poppy jasper (Morgan Hill, California), Kinradite
- Kind: Variety
- Classification: Rocks › Sedimentary rocks › Chemical and biochemical
- Crystal system: Trigonal
- Hardness (Mohs): 6.5–7
- Specific gravity: 2.5–2.9 g/cm³
- Refractive index: 1.54
- Lustre: Dull
- Transparency: Opaque
- Colours: red, yellow, green, cream, white, pink, brown
- Streak: White
- Cleavage: None
- Fracture: Breaks with a smooth, shell-like surface
- Composition: Mostly very fine-grained quartz and chalcedony (SiO₂); its colour and look come from iron oxides (hematite, goethite), clay and other minerals. Britannica ties the brick-red to brownish red to hematite, yellow and brown to goethite, and yellowish white and grey to clay.
- Texture: A dense, opaque mass of grains too fine to see by eye, taking a very good polish. Solutions moving through the rock can create dendritic, banded, spotted, veined or brecciated patterns.
- Value ladder: 5/9 step, Ornamental stone

Jasper full of coloured orbs and rings: a pattern of radiating crystals in silicified volcanic rock, best known as ocean jasper.

Orbicular jasper is a kind of jasper that, when cut and polished, shows variably coloured orbs, rings or rounded zones. The orbs form in highly silicified volcanic rocks called rhyolite or tuff, where fine, needle-like crystals of quartz and feldspar grow outwards from a centre in radiating clusters. It is sold under different trade names depending on its source: “ocean jasper” from Madagascar and “poppy jasper” from Morgan Hill in California are the best known.

## How does it form?

Orbicular jasper comes from silica-rich volcanic rocks: rhyolite lavas or deposits of volcanic ash (tuff). As the rock cools, or later as hot waters alter it, fine needle-like crystals of quartz and feldspar grow outwards from a centre in radiating clusters. These clusters are called spherulites and are usually 1–3 mm across. Then abundant silica is deposited in the rock, which becomes completely silicified into a hard, opaque stone. The colours of the orbs and the background come from iron oxides and hydroxides scattered through the rock.

The ocean jasper of Madagascar formed in this way: the deposit began as a rhyolite lava flow and was later completely silicified.

## What is it used for?

- **Ornamental stone:** because it looks very attractive when polished, it is made into cabochons, beads, pendants and ring stones.
- **Decorative objects and carving:** ocean jasper is made into spheres, eggs and small carvings.
- **Collecting:** specimens from different deposits attract collectors with their patterns and colours; Morgan Hill's poppy jasper is also on display in the town's museum.

## The story of ocean jasper

Ocean jasper comes only from the Analalava area of north-western Madagascar. Chalcedony deposits in the area were first mentioned by the French mineralogist Alfred Lacroix in 1922. The first working, near the village of Marovato, lies right on the shoreline; workers come by boat at low tide to dig the stone, and because there is no road the stones also leave by boat. Further inland at Kabamby, the stone has been collected from the surface since 2002. The name “ocean jasper” was given by Paul Obeniche and Eugene Mueller, who introduced it at the Tucson show in 2000. For jasper in general, see the [jasper](/en/stones/jasper/) page.

## How to recognise it

- An opaque background holds orbs from a few millimetres to centimetres across, ringed or spotted; on a cut face they look like eyes or flowers.
- Some orbs have a hollow centre lined with small, sparkling quartz crystals (druse).
- Like jasper it is hard (6.5–7): it scratches glass, and a steel knife cannot scratch it; it takes a good polish.
- Its colours vary widely: green, cream, white, pink, red and yellow can appear together; the colour comes from iron oxides and hydroxides.

## Fakes and imitations

- Ocean jasper comes only from north-western Madagascar. Spotted jaspers and volcanic stones from elsewhere can look like it but are not ocean jasper, so stating the source of the stone matters.

## What determines its value?

Value depends on how distinct the orbs are and on the variety and arrangement of colours: sharply ringed orbs in vivid, harmonious colours are the most sought after. Orbs with centres lined with sparkling quartz crystals and crack-free, well-polished pieces also add value. Because ocean jasper comes from a single region and is mined under difficult conditions, it is in more demand than other spotted jaspers. Still, jasper is a plentiful ornamental stone, and much of its value comes from the pattern and the workmanship.

This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment.

## Myths and misconceptions

- Myth: Ocean jasper is named after forming in the sea or on the ocean floor. Fact: The stone formed from a rhyolite lava flow that was completely silicified. It was named because its patterns recall waves and ripples, and because the first working lay on a shore that could only be reached at low tide.
- Myth: Ocean jasper is a true jasper in the scientific sense. Fact: Ocean jasper and similar orbicular stones are in fact highly silicified rhyolite or tuff; they are known as “jasper” in the ornamental-stone trade, but the name is commercial, not scientific.

## What is it believed to be good for?

This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment.

- Today crystal-therapy sites claim that ocean jasper relieves stress and brings calm and joy.
- The same sources claim that the stone keeps nightmares away and “clears negative energy”.

What science says: There is no scientific evidence that orbicular jasper reduces stress, brings joy, prevents nightmares or clears any “energy”; its coloured orbs are a pattern made by clusters of crystals that grew in volcanic rock. Persistent sleep problems and anxiety call for a doctor.

## Did you know?

- Marovato, the village near the ocean jasper working in Madagascar, means “many stones” in Malagasy.
- A photograph of ocean jasper appeared in a mineral encyclopedia in 1977 and prompted years of searching for its source; the stone was found again only in October 1999 on the shore at Marovato and was introduced at the Tucson gem show in 2000.
- The town of Morgan Hill in California is so closely linked with poppy jasper that an international film festival held every year since 2004 is named after the stone.

## Where is it found?

- Marovato, Ambolobozo, Analalava, Sofia Region, Madagascar (Major deposit): The shoreline working where “ocean jasper” was found again in 1999; it can only be seen and collected at low tide
- Kabamby, Analalava District, Madagascar (Known locality): Further inland, dark green and golden-yellow ocean jasper collected at the surface over an area of about 15 miles; worked since 2002
- Morgan Hill (slopes of El Toro), Santa Clara County, California, USA (Major deposit): The best-known source of “poppy jasper”; the deposits lie on private land
- Nebraska, USA (Known locality): Orbicular jasper occurs in altered rhyolite beds known for a variety of jaspers and agates; no exact site is given

## Sources

- [Orbicular jasper](https://en.wikipedia.org/wiki/Orbicular_jasper), Wikipedia
- [Jasper](https://en.wikipedia.org/wiki/Jasper), Wikipedia
- [Ocean Jasper](https://www.alexstrekeisen.it/english/meta/oceanjasper.php), Alex Strekeisen, Atlas of rocks and minerals
- [Orbicular Jasper](https://www.gemdat.org/gem-27171.html), Gemdat.org
- [Jasper](https://www.gemdat.org/gem-2082.html), Gemdat.org
- [Jasper](https://www.minerals.net/mineral/jasper.aspx), Minerals.net
- [Kinradite](https://minerals.net/variety/kinradite), Minerals.net
- [Morgan Hill, California](https://en.wikipedia.org/wiki/Morgan_Hill,_California), Wikipedia
- [Analalava](https://en.wikipedia.org/wiki/Analalava), Wikipedia


Source: https://taslar.bumba.tr/en/stones/orbicular-jasper/ · Licence: CC BY-SA 4.0