This is the skin that section wears good corvine skin to be not a crow, lap because of there is black on Tian Huangshi only and adorn, on body of just like crow " black " , so that place contains this kind the Tian Huangshi of black skin is called " corvine skin Tian Huangshi " , also abbreviation " black Pi Tian " . Its color is scarlet, alike in spirit agate, a kind be stone of puddle of field yellow stone -- agate freezes, because its glorious is bright, time excessive colour, with gem medium agate is similar, friend name. Skin of Huang Longyu's crow, kind water is good, sun's rays also can be passed through. The black, ash of skin of crow of yellow dragon jade deliver quality by low iron ion and such cold tone jade green is become. Corvine skin, those who point to is the jade flesh that seed expects, be lapped rise by black skin. Jade flesh has red, white, yellow. The crust of corvine skin is black slant grey, have thin branch, say efflorescent Hei Qin is degenerative commonly cliff is more, jade changes rate taller, bath is spent tall, jade flesh lukewarm embellish is exquisite. The crow of monolayer can be appeared below Pi Deng, its flesh is qualitative easily appreciation, if there is one again inside corvine skin, 2 layer wampee or Bai Pi criterion hard the lamp is illuminated identify. The corvine skin of top grade is coriaceous and exquisite, without motley, without arenaceous spot, it is makings of god-given high-quality goods seed. Of skin of crow of yellow dragon jade because geological activity boils,forming is fall in brook, the pebble shape jade that be carried for a long time to erode by brook and forms expects, have already can viewing and admire a gender is the most high grade jade carving makings. Because be bumped for a long time, the part with the inferior hardness in jade makings already was dropped by abrasion, the part that remain comes down is eroded bath spends tall, feel the egg record of exquisite, Wen Run is excellent jade makings.