How is jasper stone formed?
Jaspers are also known to form when volcanic ash or fine pyroclastics are cemented into a solid material from the precipitation of silica from solution. The cementation process is sometimes so aggressive that the sediment, ash or volcanic particles are dissolved or recrystallized into microcrystalline quartz.
Where does Orbicular Jasper come from?
northeast Madagascar
Poppy-patterned jasper or poppy jasper is the varietal name for material from several locations, but the most well known is from Morgan Hill, Santa Clara County, California. The trade name ocean jasper is used for a variety found along the intertidal shores of northeast Madagascar.
Is ocean jasper an Orbicular Jasper?
What is Ocean JasperTM? Ocean JasperTM is a trademarked name for a multicolored stone from Madagascar, typically with spherical patterning. Although commonly described as an orbicular jasper, the most recent research suggests it is the mineral chalcedony instead.
What is Orbicular ocean jasper?
Ocean Jasper, also known as Orbicular Jasper or Cellular Jasper, is a very rare variety of Jasper, a silicon dioxide mineral, and a member of the Quartz family. Its defined by circular “orb” like patterns that can be seen as green, brown, blue, yellow, grey, white, pink or red.
What is jasper stone made of?
Jasper, an aggregate of microgranular quartz and/or chalcedony and other mineral phases, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron(III) inclusions.
How is Dendritic jasper formed?
Jasper is usually formed from old sediments (or volcanic ash flows) that have been glued (and at times replaced) with silica. Flow patterns of the original material are often easy to see.
Where is Orbicular Jasper found?
Madagascar
Orbicular jasper also known as ocean jasper is actually a kind of highly silicified rhyolite thas was found on the northwestern coast of Madagascar near by the village of Marovato, hence its name ocean jasper.
Does jasper come from the ocean?
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.
How are ocean jaspers formed?
Ocean jasper is characterized by the presence of small spherical aggre- gates (spherulites, or “orbs”), just a few millimeters in diameter, that derive from a process of alteration and silicification of volcanic tuff and rhyolite flows.
How is poppy jasper formed?
Poppy Jasper is an orbicular jasper. The orbicular jasper is likely formed by the metasomatic volcanic activity. Hot fluids carrying dissolved silica and iron migrating through porous volcanic rock filled in the holes with iron minerals and silica.
What is unique about jasper stone?
Jasper stone is always multicolored with a unique and consistent pattern habit. The color palette is usually along the earth color spectrum, with the common colors being red, green, yellow, or green. Its name comes from the Latin and Old French words for spotted or speckled stone.
Is jasper a rock or crystal?
Jasper is an opaque form of Chalcedony, which is a microcrystalline variety of the mineral Quartz. It often contains an abundance of impurities, and therefore some regard it as a rock instead of a mineral.