AI Appraisal Estimate

This item is a stemmed goblet crafted from slag glass (also known as marble glass or mosaic glass), a type of opaque glassware characterized by its multi-colored, swirled appearance created by mixing different batches of molten glass. The aesthetic of this piece is dominated by a dramatic marbling of deep amethyst or charcoal black swirls integrated with milky white and translucent lavender-hued streaks. The physical construction consists of a wide, slightly flared bowl that tapers into a rounded base, supported by a short, pedestal-style stem and a circular foot. A notable physical feature is the prominent vertical seam line visible on the bowl and base, which indicates that this item was produced using a press-mold manufacturing process, common in mass-produced American art glass from the mid-20th century. The marbling is most intense at the rim and tapers into darker concentrations at the base of the bowl. Regarding condition, the goblet appears structurally intact with no large chips or cracks visible along the rim, though the glass surface shows a faint patina of dust and some minor surface artifacts typical of mold-blown glass. The craftsmanship is consistent with decorative household glassware from the 1950s or 1960s, a period when slag glass enjoyed a revival in popularity through manufacturers such as Imperial Glass, Westmoreland, or Fenton.

Based on my examination of the submitted details, this goblet is a classic example of American mid-century pressed slag glass, likely produced by the Imperial Glass Company or Westmoreland Glass between 1950 and 1970. The 'Purple Slag' or 'Amethyst Slag' coloration is characteristic of the era's revivalist style. The visible mold seams are consistent with high-volume press-molded manufacturing rather than hand-blown art glass. The structural integrity appears excellent; the absence of chips on the rim or 'flea bites' on the base foot maintains its utility and secondary market appeal. Market demand for slag glass is currently stable but heavily saturated, with high supply for standard utility shapes like goblets compared to specialized animal disparages or larger vases. Comparable sales for single amethyst slag goblets typically fall within the $20 to $50 range depending on the specific manufacturer's mark (such as the Imperial 'IG' logo). Limitations: This valuation is based on visual data. A physical inspection is required to check for 'sick glass' (internal clouding), hairline heat cracks, or microscopic surface scratches not visible in photos. Verification of a maker's mark on the interior base would confirm the specific manufacturer and could refine the valuation. Scientific testing is unnecessary for this category of collectible, as its value is driven by decorative appeal rather than historical rarity.