Jadeite is found only in metamorphic rocks.
Olivines also occur in metamorphic environments.
It can also occur in metamorphic rocks.
Perovskite, calcium titanate mineral (CaTiO3) found as brilliant black cubes in many mafic igneous rocks, in their associated pegmatites, and in metamorphic contact zones.
The southern zone consists of metamorphic rocks (gneiss, quartzite, marble, and others) to which most researchers attribute a Precambrian age (more than 540 million years old).
Hälleflinta is essentially metamorphic (altered by heat and pressure) in origin and occurs with gneiss, schist, and granulite, especially in the Scandinavian Peninsula, where it is regarded as being very characteristic of certain rock layers.
Zeolite facies, one of the major divisions of the mineral facies classification of metamorphic rocks, the rocks of which formed at the lowest temperatures and pressures associated with regional metamorphism.
On the other hand, crystalline and metamorphic (heat-altered) rocks, which represent powerfully developed chains in the central part of the Alps, appear in the Carpathians as isolated blocks of smaller size surrounded by depressed areas.
It may also be found in low-grade metamorphic rocks and as authigenic albite in certain sedimentary varieties.
Among the formations building these blocks are ancient crystalline and metamorphic cores onto which younger sedimentary rocks—for the most part limestones and dolomites of the Mesozoic Era (about 250 to 65 million years ago)—have been overthrust.
This highest Carpathian massif is built of crystalline (granite) and metamorphic rocks, but the northern part contains, upthrust from the south, several series of limestone rocks with associated karst, or water-incised, relief forms.
