This appears to be a vintage Park Lane gold-tone filigree bar pin featuring an ornate scrollwork setting around a faceted black center stone.

The estimated resale market value for this pin as an unmarked or unbranded vintage costume jewelry piece typically ranges between $10 and $20. 

Because it consists of base metals (gold-tone plating) and a glass or faux-gemstone center rather than precious metals or genuine gems, its value rests entirely on its aesthetic appeal to vintage collectors. 

Value Breakdown

• Generic Unmarked Costume Jewelry: $10 – $15

• Identified Brand Value: If a buyer recognizes the design pattern as an unsigned piece from a mid-market vintage manufacturer like Jewels by Park Lane or 1928 Jewelry Company, the value increases slightly to $15 – $25