Hi Lisa thanks for writing in. Art deco you say? Good for you! PLAT antique was a popular choice for jewelry from the early 20th century. Plat antique jewelry was especially popular in high quality Art deco jewelry. The point is: it is more than likely made of metal that's at least 85% platinum. Platinum is very expensive today and New platinum jewelry may be made of metal that's only, wait for it - 58.5% platinum!
