vintage coffee mug white milk glass Anchor Hocking FireKing line 1960s D handle

vintage coffee mug white milk glass Anchor Hocking FireKing line 1960s D handle solitary orphan coffee mug by FireKing milk glass has "ring of fire" irridescence when held up to sunlight round mug with ergonomic D handle standard coffee mug sized marked "FireKing WARE 5 Oven Made in USA" measures approximately 4" opening to handle x 3 1/4" opening x 3 3/8" tall excellent preowned stored and used vintage condition - circa 1960s - please see photos - looks like seldom / gently used - no cracks ,chips or staining noted Medium Sage Box 1