a rectangular black onyx pendant set in a textured silver metal frame on a dark chain
The back of the pendant shows a textured, dark, somewhat uneven stone surface inset within the metal casing, which features noticeable adhesive or residue along the bottom and side edges.
The appearance of the backing provides context regarding the construction of your piece:
Based on the construction, materials, and secondary marketplace data, a vintage rectangular black onyx pendant on a 23-inch sterling silver chain generally holds a market value of $45 to $80 USD.
The exact value depends heavily on the materials and origin:
Sterling Silver & Natural Onyx: If the metal frame and chain are stamped with a hallmark like .925 or 835, standard vintage pieces sell on platforms like eBay and Etsy in the $45 to $70 range. If it features a known maker's mark or origin—such as vintage Mexican Taxco silver masterwork—the value can shift closer to $60 to $80+.
Base Metal or Stainless Steel: If the setting is unhallmarked base metal, silver-plated, or stainless steel, the value drops closer to $15 to $30
Key Observations
Texture: The unpolished, slightly grainy texture on the reverse side is highly typical for the back of an authentic, natural black onyx slab. [1]
Setting Style: The stone is secured within a bezel or frame setting. Rather than being a thick, solid block of stone, it is likely a thin slice or tablet of onyx.
Adhesive Residue: The greenish-yellow crust visible at the bottom edge is old jeweler's glue or epoxy. Over time, vintage or handcrafted jewelry can exhibit this kind of adhesive aging as the glue dries out and becomes visible