Silver-mounted crystal dish and box by l'Escalier de cristal

Extremely rare engraved crystal square box with a square dish mounted in a sterling silver frame. Set realized by l'Escalier de Cristal, signed in the back. Engraved crystal decorated with flowers. Sterling silver framed decorated with chiseled flowers and leaves. Stamped with the silver guarantee mark and the silversmith mark "AC" for Auguste Claire (silversmith active starting from 1895).