is strong.

The spirals neatly match the Archimedian shape, and their center is at the centre of the ring, which could be cut that way by turning the jade with the stylus fixed in place. The spiral carvings are also noticeably more uniform than other jade patterns.

The rings date from at least 552 BC, and while there is no evidence of earlier spiral rings, Lu says nobody has been looking for them.

Meanwhile, Lu is turning back to his graduate work in physics. On Friday he has to talk to astronauts on the International Space Station about an experiment he has on board to study how liquids and gases change phase.Three of the four defendants in the 2012 murder of Salt Spring, St James, resident Rodell Hall will face preliminary examination in the Montego Bay Resident Magistrate's Court on March 31.

Clyde and Nesta Morlese, of Patty Hill in Hanover and Sheldon Russell, of Salt Spring, had their bails extended on Wednesday, while presiding magistrate Wilson Smith issued a bench warrant for co-defendant Damane Samuels who was not present.

The four were charged in connection with Hall's shooting death on February 4, 2012, after the taxi in which he was a passenger was reportedly ambushed by gunmen about 2:10 a.m. along the Salt Spring main road. The passengers were ordered out of the car and Hall attempted to escape, but was shot and later died.

Clerk of court Sheryl Robinson told