Metamorphic Minerals

Texture and Microstructure

Metamorphic Rocks

Ocean Jasper

Ocean Jasper, a marketing term for a spherulitic variety of orbicular jasper, is a variety of jasper which contains variably colored orbs or spherical inclusions or zones. Like other jaspers, the rock is characterized by the presence of spherical aggregates a few mm in diameter (normally 1 to 3) that are called spherulites or orbs. These microstructures formed during the alteration of former tuffs or rhyolites, accompanied by extensive deposition of SiO₂ (silicification).

This new rock has been found along the northwest coast of Madagascar after years of unsuccessful searching. The deposit formed as a rhyolite flow but has been completely silicified. The rhyolitic eyes or orbs come in an astonishing array of colors and color combinations. The background can be white, pink, green, red, or yellow. Botryoidal formations as well as white and deep green druzy are also common. The deposit has been discovered at the edge of the ocean. It can only be seen and collected at low tide. The area has no road so the material must be transported to civilization by boat. (The Lapidary Journal)

Ocean Jasper only comes from one place in the world, northwestern Madagascar in the Analalava district of the Sofia region in the former province of Mahajanga (Fig.1):

1) Marovato: The mine near the village of Marovato is directly on the shoreline. The material there comes in a wide range of colors. During low tide the miners would come in by boat to dig up and remove the Ocean Jasper. The name Marovato means many stones in Malagasy.
2) Kabamby: The mine near the village of Kabamby is further inland. The material there tends to be dark green and golden yellow, sometimes cream and red. The Kabamby deposit was first mined in 2002 and continues to be collected today. Kabamby Ocean Jasper is found through surface mining across an approximately 15 mile area

Fig.1 Location of Ocean Jasper mines. 1) Marovato mine, 2) Kabamby mine.

The existence of chalcedony deposits in the area was first written about in Alfred Lacroix's Minéralogie de Madagascar published in 1922. However orbicular material is not specifically mentioned. Dr. Klaus Thalheim has documented one of the earliest known examples of Ocean Jasper, a slab from Kabamby. It belonged to Richard Baldauf, an early 20th century German collector.

In 1977 a photo of Kabamby Ocean Jasper was included in Grund's Encyclopédie des Minéraux (Encyclopedia of Minerals), sparking interest in the stone. Ocean Jasper was rediscovered at the turn of the millennium by Paul Obeniche. Like many others, he first saw it in Grund's encyclopedia. Paul launched a series of excursions to locate it. Ocean Jasper was found again in October of 1999, on the shoreline outside the village of Marovato. The original Kabamby material was found nearby later.

Ocean Jasper was introduced to the general public at the Tucson gem show in January of 2000. It was named there by Paul Obeniche and Eugene Mueller. They called it Ocean Jasper because it resembles the waves and ripples of water and the mine was first discovered along the shoreline, originally accessible only at low tide.

Fig.2: The shoreline of Marovato where Ocean Jasper is collected. From Enter the Earth.

Fig.3: In Kabamby material is collected through surface mining. From Enter the Earth.

Fig.4: Ocean jasper. Madagascar. From Treasures of Light Crystals

Fig.5: Ocean jasper. Madagascar. From Treasures of Light Crystals

Fig.6: Ocean jasper. Madagascar.

Fig.7: Ocean jasper. Madagascar.

Bibliography

• David Shelley (1983): Igneous and metamorphic rocks under the microscope. Campman & Hall editori.
• E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc
• Anthony R. Phillpotts & Jay J. Ague: Principles of igneous and metamorphic petrology. Cambridge editore.

Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)	Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)
Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)	Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)	Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)	Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)
Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides. Ocean Jasper from Madagascar. PPL image, 1x (Field of view = 9mm)	Chalcedony spherulites (Growth interference between orbs, producing irregular polygrams). Ocean Jasper from Madagascar. XPL image, 1x (Field of view = 9mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL (with Compensator plate) image, 2x (Field of view = 7mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)
Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL (with Compensator plate) image, 2x (Field of view = 7mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)
Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 2x (Field of view = 7mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 2x (Field of view = 7mm)
Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. The Growth interference between orbs, producing irregular polygrams. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)
Chalcedony spherulite. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulite. Note the fibrous structure. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulite. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)
Chalcedony spherulite. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulite. Note the fibrous structure. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulite. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)
Chalcedony spherulite. Note the fibrous structure. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulite. Note the fibrous structure. Ocean Jasper from Madagascar. XPL (with compensatore plate) image, 10x (Field of view = 2mm)	Chalcedony spherulite. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the fibrous structure. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the fibrous structure. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)
Chalcedony spherulite. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulite. Note the fibrous structure. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the regular contact between spherulites. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the regular contact between spherulites. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the regular contact between spherulites. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)
Chalcedony spherulites. Note the regular contact between spherulites. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the regular contact between spherulites. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)
Chalcedony spherulites. The colors is due to Fe-oxides/hydroxides (which are also found scattered in the rock). Ocean Jasper from Madagascar. PPL image, 10x (Field of view = 2mm)	Chalcedony spherulites. Note the regular contact between spherulites. Ocean Jasper from Madagascar. XPL image, 10x (Field of view = 2mm)