The "Mexico" stamp confirms this is a The "Mexico" stamp confirms this is a vintage Mexican Modernist brass torque collar necklace. 

During the mid-to-late 20th century (particularly the 1970s and 1980s), Mexican jewelry workshops—most famously in Taxco—produced highly popular, avant-garde brass and sterling silver neck cuffs. These pieces are highly collectible for their minimalist, sculptural forms and the natural, rich patina that the brass develops over time.

The resale value for a vintage unbranded Mexican brass torque collar necklace generally ranges between $30 and $60 USD. A very similar vintage V-shaped piece stamped "Mexico" recently sold on eBay for $48 USD. 

Value Factors

• Base Material: Since this piece is solid brass rather than sterling silver (which would be stamped "925"), its value relies entirely on its design, age, and collectibility rather than precious metal weight. 

• Maker Marks: An unbranded piece marked only with "Mexico" or "Hecho en Mexico" stays in the lower double-digit range. However, if you find an artisan signature or registry mark (like Tony Guerrero or Luciano Bustamante), the value can shift closer to $100 to $200+ USD