对于颈椎病,下列说法不正确的是
http://img2.ph.126.net/OQxWVDVBDcyMXCNf-CdVRQ==/13229323915433285.gif
http://img2.ph.126.net/vAno5GeCTTLbEaJRd1fkPg==/1134907106114843546.gif
http://img0.ph.126.net/nbtUVRl6TVDgov2azbKG0Q==/2891873910742666236.gif
某种蓝色宝石,折射率1.62,强二色性,密度3.05g/cm3,它应该是:( )