The crenellated cloud pattern Jade is unique to the Hongshan Culture of North East China. This example is exceptional for its  size (17.0cm).Very few extant pieces. When considering that it is 'created' ~5000 yrs.ago in pre-history;one can go into various streams of fantasies,reflecting on the culture that can support the artistic and technical expertise to 'create' this marvellous piece from such an ordurate Jade (Nephrite)!

A similar piece is in the Freer Gallery of Art,Washington.(1991.52) presented to the gallery by Therese and Erwin Harris of Baltimore,Maryland. The length is L:17.2cm(not much difference) but have seven pairs of 'teeth';two more than the above.More detailed info can be obtained from the May 1993 article in Orientations Magazine titled "A Hongshan Jade Pendant in the Freer Gallery of  Art by Jenny F. So."

3rd.Jan.'08- There is another Crenellated Pendant,more similar in design and infact longer ~20.0cm in the collection of the reknown Hong Kong Collector - Dr.Simon Kwan. Unfortunately my copy was borrowed and never returned but believed the title is Archaic Jade Collection of Dr.Simon Kwan and commented by  one of the foremost Jade 'Expert' - Yang Boda. CAUTION:All my notes are ad-hoc, as too lazy to go through my pile of Jade Books.

To know or expand your  knowledge on Jade,please visit the Friends of Jade website ,given in the link.