Anchor Hocking Fire-King mug (not authenticated)

This is a vintage milk glass mug featuring an iridescent or pearlescent finish, displaying a subtle rainbow sheen under the lighting conditions. The piece is constructed with a rounded, smooth body and a classic curved handle attached to the side. The overall appearance is consistent with mid-20th-century glassware popular in American households. Visible on the recessed bottom of the mug is a molded maker's mark comprising a shield logo with the letter 'F' in the center, surrounded by the text 'HEAT PROOF' arched across the top and 'USA' at the bottom. The condition appears well-preserved with a glossy surface sheen and no major chips or cracks immediately apparent in the image, though minor manufacturing flaws or surface wear common to vintage glassware cannot be entirely ruled out without physical inspection. The attribution to Anchor Hocking rests entirely on the molded Fire-King shield logo visible on the base of the item, which serves as a visual indicator rather than a guarantee of period manufacture.

Based on what I can see in the photograph, this mug presents a milk glass body with an iridescent finish and bears a molded mark on the base featuring a shield logo with the letter 'F' and the text 'HEAT PROOF USA', which is consistent with items commonly attributed to the Fire-King line associated with Anchor Hocking. However, I cannot verify from a photo alone whether this piece is an authentic mid-century production or a later reproduction, as visible markings can be replicated. Based on the assumption that this attribution is correct and that the piece is in well-preserved condition with no major chips or cracks visible, similar vintage glass mugs typically command a market range of $15 to $35 among collectors of mid-century kitchenware. General demand for retro glassware remains steady, though values fluctuate based on exact color variations, condition upon physical handling, and current collector interest. To confirm authenticity and establish a more precise value, an in-person examination by a qualified appraiser, physical inspection of the glass weight and texture, and thorough hallmark verification would be necessary. If physical inspection were to reveal that this item is a modern replica, reproduction, or made 'in the style of' rather than a period piece, the value would likely decrease significantly, typically falling into the $5 to $10 range as a decorative novelty rather than a collectible vintage piece.