Mastery of Design: The Goldstein Emerald, c. 1940

Emerald, Ruby, Diamond and Gold Ring
American, 1940s
The Victoria & Albert Museum

Made in the early 1940s, the angular geometry of this ring typifies much of the jewelry of the  Art Deco period, but also shows the then-growing trend toward softer forms.  By the 40s, jewels relied on angled curves, volutes, and flourishes with an increased sense of three-dimensionality. 

While still angular, this ring, made in the U.S., is set with a central cabochon emerald for softness.  This is flanked by square-cut rubies and diamonds which tend toward the earlier, more geometric standards.