Oval Lavender Turquoise or Phosphosiderite Prong-Set Ring

This item is a large, hand-held fashion ring featuring a prominent oval-shaped cabochon gemstone. The stone exhibits a striking color palette of pale mint green and soft lavender-pink, bisected by a dark green or grey dendritic matrix that patterns the surface. Based on the pastel coloration and veining, it appears to be either high-grade ‘Lavender’ Turquoise or possibly Phosphosiderite. The stone is roughly 30-35mm in length and is secured by a distinctive ten-prong setting—five on each side—crafted from a dark, possibly oxidized or blackened sterling silver metal. The craftsmanship suggests a contemporary artisanal or Southwestern-inspired design, though lack of visible hallmarks prevents definitive artist identification. The condition of the gemstone appears smooth and well-polished with a vitreous luster, showing no immediate signs of surface fractures beyond the natural matrix inclusions. The metal shows a dark patina consistent with intentional oxidation for stylistic contrast. The setting is robust, with the prongs appearing structurally sound and evenly spaced, indicating quality benchwork. This piece represents a unique specimen likely dating from the late 20th to early 21st century.

I have examined the provided images of this large, oval cabochon fashion ring. The gemstone exhibits the distinctive 'soft' color palette of high-grade Lavender Turquoise or Phosphosiderite with a natural dendritic matrix. The ten-prong setting is executed with professional-grade symmetry, and the intentional dark patina on the sterling silver mounting suggests a contemporary artisanal origin, possibly from a high-end Southwestern boutique. The stone appears to be approximately 25-30 carats based on the reported 30-35mm length. Visually, the luster is consistent with a well-polished, stabilized stone, and no structural fractures are evident. The market for unique, 'statement' lapidary jewelry remains strong among collectors of boutique gemstones. Valuations for similar unhallmarked artisanal pieces typically fall in the mid-hundreds, though a documented artist hallmark could increase this by 40-50%. Limitations: A definitive identification between Lavender Turquoise and Phosphosiderite cannot be made via image alone; a Mohs hardness test and refractive index (RI) reading are required. Furthermore, without a physical inspection, I cannot confirm the presence of a '925' hallmark or detect potential stabilization treatments common in this turquoise variety. Verification of the metal's purity via an acid or XRF test and provenance documentation from the artist would be necessary for a final, certified valuation.