I have always loved the colour of these rings, and have owned quite a few over the years infact it is what started my own extensive jewelery collection, I prefer silver on myself so these two are for sale in my shop they are from the late 1950's or 1960's and in 10 kt gold.
It took me years of research to find out what the stone is of course I know about Vaseline glass in vases and pots but not in jewelery my own rings are Art Deco or Art Nouveau so I had no idea what these contemporary rings were until about a year ago they are almost ugly in their beauty.
A BIT ABOUT VASELINE GLASS:
Also known as uranium glass, vaseline glass glows bright green under ultraviolet light, thanks to the uranium oxide added to the glass in its molten state. In natural or indoor light, vaseline glass has a yellow or yellow-green tinge with an oily sheen, which is where its name comes from. Vaseline glass is not to be confused with Custard glass and Burmese glass, which also glow under ultraviolet light. While vaseline pieces are transparent or translucent, these pieces are opaque.Uranium oxide was first used as a coloring agent in the 1830s; vaseline glass was produced... commonly from the 1840s through World War I, though it was most popular from the 1880s onward. A variety of companies produced it, including Adams & Co., Steuben Glass, Cambridge Glass Co., and Baccarat, which released its first vaseline glass piece in 1843 under the name “cristal dichroide.”
Different companies called its distinctive color different names, including citron, jasmine, golden green, mustard, Florentine, and canary. Pieces could also have different exterior color finishes, like satin, opalescent, iridescent, rubina verde, and yellow-green.
Vaseline glass was produced in a variety of styles over the years, from Victorian to Art Deco. During the Great Depression, some manufacturers added iron oxide (rust) to the vaseline glass mixture in an effort to make the glass look greener in natural light. As a result, vaseline-glass purists exclude this Depression-era glass from the vaseline-glass family, since vaseline glass in the traditional sense does not include iron oxide in its composition. Carnival glass was also produced in vaseline glass varieties, which generally had a marigold, iridescent look.
Thank You to Collectors weekly for the article, link: http://www.collectorsweekly.com/glassware/vaseline-glass