Jadeitite is a

metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, cau ...

found in

blueschist Blueschist (), also called glaucophane schist, is a metavolcanic rock that forms by the metamorphism of basalt and rocks with similar composition at high pressures and low temperatures (), approximately corresponding to a depth of . The bl ...

-grade metamorphic

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its ow ...

s. It is found in isolated metasomatically altered rock units within

serpentinite Serpentinite is a rock composed predominantly of one or more serpentine group minerals, the name originating from the similarity of the texture of the rock to that of the skin of a snake. Serpentinite has been called ''serpentine'' or ''ser ...

associated with

subduction zone Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

environments. Jadeitite consists almost entirely of the

pyroxene The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents calcium (Ca), sodium (Na), iron (Fe II) ...

mineral

jadeite Jadeite is a pyroxene mineral with composition Na Al Si2 O6. It is hard (Mohs hardness of about 6.5 to 7.0), very tough, and dense, with a specific gravity of about 3.4. It is found in a wide range of colors, but is most often found in shades ...

and is typically mined as a source of the ornamental rock or gemstone,

jade Jade is a mineral used as jewellery or for ornaments. It is typically green, although may be yellow or white. Jade can refer to either of two different silicate minerals: nephrite (a silicate of calcium and magnesium in the amphibole gro ...

. Occurrences include

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

, Guatemala, Japan,

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia Russia (, , ), or the Russian Federation, is a transcontinental coun ...

and in the

Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although th ...

of western North America. Over 100 axe heads made from jadeitite quarried in northern Italy in the

Neolithic era The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts ...

have been found across the British Isles. Because of the difficulty of working this material, all the axe heads of this type found are thought to have been non-utilitarian and to have represented some form of currency or be the products of gift exchange.

References

;Notes ;Sources *Harlow, G.E.
Jadeitites, albitites and related rocks from the Motagua Fault Zone, Guatemala
''Journal of Metamorphic Geology'' 12 (1), 49–68 (1994) *Sorensen et al.
"The origin of jadeitite-forming subduction-zone fluids: CL-guided SIMS oxygen-isotope and trace-element evidence"
''American Mineralogist'', Volume 91, pages 979–996 (2006) *Sorensen, S. S

Geological Society of America (GSA) 2005 Annual Meeting

''Geotimes'', August 2002 Metamorphic rocks {{petrology-stub