This distinguished 15 different types, some of which, including the highly polished jadeitite
'Carnac type' axeheads from around the Gulf of Moribhan, Brittany, had been transformed and repolished to serve regional stylistic requirements.
Jade is a cultural term for two rare metamorphic rocks known as jadeitite and nephrite that are both extremely tough and have been used as tools and talismans throughout the world.
The jadeitite (or jadeite jade) is a sort of scar tissue from some collisions between Earth's plates.
Then, after plate movement changed direction about 100 million years ago, a second collision between one of these slices and the North American plate reset the mica clocks in jadeitite found on the northern side of the fault to 70 million years.
The Breamore jadeitite
axehead and other Neolithic axeheads of Alpine rock from central southern England.
Le probleme europeen des haches d'apparat en jadeitite et roches voisines.
The metamorphic metabasites, especially edogites, jadeitites and glaucophanites, have a shock-resistant character particularly useful in an axe.
Some 10 km south of the Motagua, alluvial jadeitite found in the Rio El Tambor is significant for its origin across a major fault, long considered the southern geological limit for jadeitite occurrence.
Matching jade artefacts with jadeitite sources has been a problematic endeavour.
However, for a jadeitite source material to be considered the counterpart of one exploited in the Formative period, it must also share the visual characteristics of Olmec jade.
The Sierra de las Minas and the highlands south of the Motagua River have recently yielded some remarkably translucent, fine-grained jadeitites that closely resemble those worked in Formative times.
Some of the recently recovered jadeitites have the combination of composition, minor minerals, and visual characteristics (details to be reported elsewhere; Harlow et al.