The top, centre and bottom rings shown in pic 1 are chalcedony while the two rings on the left and right are probably nephrite.
Except for the centre ring which is flat, all the rings have tapering sides. All the rings are undecorated and are well crafted, polished and beautiful in their plainess. Filippo Salviati writing in the Language of Adornment, said that such rings have been used in pectoral and necklace assemblages during the Zhou dynasty 1046-256 BC.
The pieces shown here, (if not fakes) are likely to date from Warring States period 475-221BC, or later.
The bottom one which is the only one polished is also more like a bi.
I think they are of the same vintage as the rings shown in Pic 1.