Chinese Stone

An uncommon stone imbedded with screw-threaded metal bar from a collector in Lanzhou Mr. Zhilin Wang. He found this stone on a field research trip to the Mazong Mountain area located on the border of Gansu and Xijiang provinces. The pear-shaped stone is extremely hard and has a mysterious black color. It is about 8 x 7 cm and weighs 466 grams. The most surprising part of the stone is the imbedded 6 cm cone-shaped metal bar which bears clear screw threads. The stone is one of the most valuable in China and in the world. There are many hypotheses about the formation of this stone, but all seem to be incredible. The screw-threaded metal bar is tightly enclosed in the black lithical material. Neither the bar’s entrance to the stone nor the exposed bar tip appear to be man-made. Moreover, the screw thread width remains consistent from the thick end to the thin end, instead of varying due to the growth of organisms. Is this a relic from a prehistoric civilization? Could it be a stony meteorite having any message from an extraterrestrial civilization for us?. How the stone was formed? It is suspected as being from outer space.