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This vintage sapphire ring stamped simply "RING" indicates it lis missing a proper hallmark for the metal purity (e.g., 10K, 14K, 18K, or 925) or the maker.
In the Jewelry trade, this often indicates the word "RING" was mistakenly engraved as a style or manufacturing code, or the piece is a reproduction. The stamp does not confirm authenticity.
Sapphires are highly valued precious gemstones, sapphires are also highly durable and ranked high on the MOHs scale of hardness. Have a professional gemologist do a conductivity test to identify if the gemstones are genuine and not glass, cubic zirconia, or synthetic corundum.
