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.