jewelry box; jewel case
A small container for storing jewelry and other precious items. The gloss 'casket' is archaic or poetic in this sense; modern English prefers 'jewelry box' or 'jewel case'.
祖母からもらった宝石箱を大切にしている。
I treasure the jewelry box I received from my grandmother.
彼女は宝石箱に指輪をしまった。
She put the ring away in her jewelry box.
Compound of 宝石 (hōseki, 'gem, jewel') and 箱 (hako, 'box'), with rendaku voicing of 箱 to ばこ.