Grande Ring Marguerite Art Deco Sapphire and diamonds

Ring daisy in white gold 18Kt and paltinium (hallmarks: dog and eagle), the center of which is adorned with a large cushion sapphire, weighing approximately 6.90 Cts (probable origin: Siam), in a surround of diamonds cut sapphires. Total weight diamonds estimated at approx. 2.00 Cts, color estimated I, clarity estimated SI. French Art Deco work, circa 1930. Gross weight: 8.16gDesign height: 2.20 cmDesign width: 2.00 cmSizeSize: 58 (diameter 18.35 / US 8.25), with spring ring. Condition: slight micro-scratches on gold and silver parts. paltinium, natural inclusions in the stones, slight irregularity of the setting, see photos.   Did you know that sapphire blue owes its hue to the presence of iron and titanium in its composition? The shade of blue varies according to the origin of the gem: the sapphires from Thailand, Cambodia and Australia, derived from basaltic rocks, are generally darker because they are rich in iron. All our engagement rings.