Glass panels-Offered is a group of nine 4" square sun tinted amethyst transom window panels. Consists of 8 plain back & one star design. I would say are of the Frank Lloyd Wright Lexfer design. The plain or smooth back panels are embossed on one edge C99 & the star one has a D. Each 4" square is make up of 19 prims or ribs. There are 13 units in this offering sold as EACH, 9 squares per unit. Most are in excellent condition. but each unit may have a panel with a slight corner chip. Panels have been lightly cleaned still having some old grime. I would say these have been sun tinted to the purple or amethyst color from manganese oxide content.