This is a Delphite blue Pyrex cup and saucer from the 1940s /1950s in the pie crust pattern, sometimes also called "king's crown". The blue tinted pyrex dinnerware was produced by Pyrex in Canada from the mid 1940s to early 1950s and can be hard to find in the U.S.
Both the cup and the saucer are in excellent condition with no chips or cracks. This listing is for one cup and saucer only. I have 3 sets available. Please note that this translucent blue glassware is particularly difficult to photograph and capture the colors accurately. I've done my best to portray the true color, but the light plays off of each surface differently, even in the same photograph. This is the light pastel blue or almost copen blue pyrex, not the turquoise blue.