This piece was made by the former Pilgrim Glass company in the United States. It is a form of Galle glass and it is made from Vaseline glass more formerly called Uranium glass. Uranium glass will glow in a violet color when exposed to an ultra violet light.
Cased and cameo glass was made of two different layers of glass of different colors, fused together by heat. The first case of layer is made in a cold. When it is finished and cooled, a second layer is blown inside the first Then the piece is placed into the furnace, so the two layers fuse together. The cameo glass of two or more colors was carved with a diamond saw or etched with acid, so that the colors of the layer underneath were visible and created a design.