The Sterling TK mark indicates that this vintage piece is crafted from 925 sterling silver and was manufactured by the Tru-Kay Manufacturing Co., an American jewelry brand founded in Rhode Island in 1946. 

The layout design features a center bar, making it functional as both a traditional brooch pin or a scarf/sash buckle slide, a style popularized by mid-century costume jewelry makers. The estimated resale value for this vintage Sterling TK rhinestone heart brooch generally ranges between $15 and $60.

The exact market value depends heavily on specific factors:

Market Pricing Examples

• Standard Chaton Rhinestone Brooches: Simple rhinestone open-heart pins or slide buckles by Tru-Kay typically sell on platforms like eBay and Etsy for $15 to $30. 

• Pristine/Art Deco Styles: Pieces that feature exceptional rhodium plating or function smoothly as versatile pendant-brooch conversions lean closer to the $45 to $60 range.