KOCH TOI ET MOI RING In platinum, set with a fine pearl and an old-cut diamond weighing approximately 1.10 ct, the shoulder set with old-cut diamonds. Circa 1900. Signed. In its original case. A diamond, natural pearl and platinum Toi & Moi ring, by Koch. Circa 1900. L.F.G. certificate attesting: perle fine d'eau de mer (natural pearl). RC : Dimensions of the pearl: 7.1 - 7.3 mm approx. TDD: 54; US: 7 1/2 (changeable). Gross weight: 4.9 g (Pt - 950).