贡

Bottom shell radical — cowrie shells were China's earliest currency, so this radical files 贡 with money/value words: 财 wealth, 货 goods, 资 capital, 贵 expensive. Marks tribute as a transfer of valuable goods. The picture is craftsman's labor (工) producing wealth (贝) presented upward to a lord.

Top 工 supplies the sound — gōng shifting to gòng with tone change. Originally a pictograph of a carpenter's square or ramming tool. Same phonetic family: 红 red, 江 river, 功 merit, 攻 to attack. In 贡 it provides the reading while the lower shell anchors the meaning of presented goods.