Vintage 10k gold filled cameo ring in great vintage condition featuring a hand-carved shell portrait. These pieces date back to the mid-20th century, roughly between the 1930s and 1950s. Key Features & Identification Material: The "10k Gold Filled" (often stamped as "10K G.F.") designation means a thick layer of 10k gold is mechanically bonded to a base metal. This is much more durable than standard gold plating. The Cameo: Most vintage rings of this style use natural conch or sardonyx shell. Authentic shell cameos are characterized by a white or cream foreground portrait against a contrasting orange or brownish-pink background. Makers: Common manufacturers for this specific style of gold-filled jewelry include Clark & Coombs (Providence, RI), who frequently used a "C&C" diamond-shaped hallmark