The precious sons of Zion; i.e. not merely the nobility, but the people of Judah in general. It is needless (as the literal interpreters of Lamentations 4:1 are compelled to do) to alter b'ne (sons) into bātte (houses) or 'abne (stones).
The comparison of men to potters' vessels is familiar to the Hebrew writers (comp. Isaiah 22:24; Isaiah 45:9).