interesting green goblet

I have collected a set of four of these over the span of about 15 years. Three are this exact color, and one is slightly more olive colored. I can find no visual marking letting me know when or by whom they were made. I have always liked the way they look, and would like to know more about them. I have purchased all of them one by one, and all at thrift shops. There are "seams" on either side, leading me to belive that they were made in a mold. Anyone have any guesses as to what company might have made these and when?