Your piece was produced by Diamond Glass-ware Company of Pennsylvania and is called Adam's Rib. Adam's Rib was often decorated with gold, silver, or black horizontal lines or trim. Many pieces can be found with an iridized finish which yours does have. As far as more info on the company The factory was first known as the Indiana Glass Company in 1891, It then changed hands 2 more times becoming Northwood company then Dugan glass It finally emerged as the Diamond glass-Ware company c1913. Two important lines were introduced in the 1920's No. 900 (Adam's Rib) was one. A fire destroyed part of the plant on June 27 in 1931, The plant never reopened. It is not cased glass but pressed glass and the color is fired on over clear glass. Beautiful piece In this market $70.00
