TURKISH PURPLE JADE
Purple or lavender-colored jade is very rare. Such rocks are known from Burma, Turkey, and parts of Central America. Purple jade from Turkey is a polymineralic metamorphic rock with a complex origin. Published research indicates that this material was originally Paleozoic- or Mesozoic-aged phonolite lava, an alkaline, intermediate, extrusive igneous rock. During the Late Cretaceous, at about 80 Ma, blueschist facies metamorphism (= high-pressure, low-temperature) altered the phonolites into rocks dominated by jadeite pyroxene, potassium feldspar, lawsonite, and aegerine pyroxene, with minor monazite, phengite, and secondary sericite.
During the Cenozoic, tectonic uplift, surficial exposure, and paleoerosion of these blueschist-facies rocks resulted in them being incorporated in landslide deposits (debris flow breccias). Turkish purple jade is collected as loose paleoclasts eroded from these Middle Miocene debris flow breccias.
Purple jade (= finely-crystalline jadeite-K-feldspar-lawsonite-aegerine metamorphite) (10.2 cm across at its widest) - blueschist facies metaphonolite from Bursa Province (probably near Akpinar in southern Bursa Province), northwestern Turkey.