Cartier Paris Art Deco Royal Blue 2.3 Carat No Heat Sapphire and Diamond Ring

Cartier Paris Art Deco platinum ring set with a GIA certified no heat Royal Blue sapphire, approximately 2.30 carats by formula, in an emerald octagonal step cut. The center sapphire is flanked by baguette and asscher cut diamonds totaling approximately 0.80 carats in a three-stone Art Deco design. Signed Cartier Paris, circa 1920s–1930s. Total weight 4.04 grams.

This Cartier Paris Art Deco sapphire and diamond ring represents the design language that made Cartier one of the defining jewelry houses of the 1920s and 1930s. The ring uses a three-stone platinum construction with an emerald-cut royal blue sapphire at the center and geometric diamond shoulders on each side. The baguette and asscher cut diamonds create the stepped architectural profile associated with Art Deco Cartier jewelry, where symmetry, proportion, and gemstone contrast mattered more than decoration for decoration’s sake. Signed Cartier Paris period sapphire rings are highly collected, especially when paired with no heat blue sapphires and original Art Deco construction.

The center stone is a GIA certified natural Royal Blue sapphire with no indications of heating. The sapphire measures 7.89 x 6.40 x 4.30 mm and is estimated at approximately 2.30 carats by formula. A no heat Royal Blue sapphire in a signed Cartier Paris Art Deco ring is significant because the stone, certification, treatment status, and maker all support the ring’s collector value.

Basaltic sapphires come from basalt-related geological environments and are commonly associated with sources such as Cambodia, Thailand, Australia, Vietnam, and other volcanic sapphire deposits. These sapphires can show deep, saturated blue color, which is why they can be visually effective in Art Deco-style platinum and diamond settings. Historically, the most famous prestige sapphire origins were Kashmir, Burma/Myanmar, and Ceylon/Sri Lanka, while modern gemological origin reporting also recognizes basaltic sources more specifically through trace element chemistry and inclusion analysis. For this ring, “Basaltic” should be presented as the GIA origin classification, not as a substitute for Kashmir or Burma. The Cartier relevance is visual and historical: Cartier favored sapphires with strong color, clean presentation, and enough transparency to hold up against platinum and diamonds, and this basaltic Royal Blue sapphire fits that design logic.