Hazel Atlas utilized their white glass (known as Platonite) in several of their lines of glass dishes. Their Moderntone dishes within the Ovide shape came in many patterns and fired on colors. Several sets were multi-color sets like the Sierra. Sierra colors were this Turquoise (Aqua), Gray, golden Butterscotch Yellow, and Rust.
This 6" bowls with straight sides is the turquoise color within the Sierra. This size bowl is thicker and heavier than most of the other pieces found in the Sierra and is an unusual find. Bowls like this one often came with a larger serving Salad Bowl in one of the four colors. The bowl does not carry the H over A Hazel Atlas mark which is unfortunately pretty typical of their glassware.
There is a lot of reflection with the photos making it difficult perhaps to note but the bowl is free of chips or breaks and the fired on color is intact except for a small gray mark noted on the exterior. The small gray mark (probably from stacking) is shown in the last two photos of the bowl. Otherwise, the bowl is as nice as new.
You may wish to see the set of three of these bowls listed separately and shown in the last photo..
Hazel Atlas Moderntone Sierra 6" Turquoise Salad / Soup Bowl