2 unique diamond pattern cobalt blue water glasses that can only be read by looking through the tumbler from the top because the letters are reverse stamped on the bottom. They are Franceshino, 300 ml glasses that are 4 1/2 inches tall by 2 1/2 inches diameter at the top. I have found several postings on ETSY going as high as $15 per glass with most right around $10 per glass and one that lists 6 for $29.95 "as is". The information I could find indicates that this pattern was from the 1970's making these about 50 years old. There are no cracks or chips and there is a visible "seam" on the exterior where glass in poured into a two-part mold during pouring/manufacturing.