King Edward VII and his graceful wife Queen Alexandra led English society to new taste levels during the early 1900s. Edwardian jewels reflected gracious delicacy with ribbons, bows, swags, and tassels. Abundant quantities of diamonds and platinum had recently been discovered in South Africa -- these materials became the hallmark of the Edwardian era.
The strength of platinum made it possible to create pieces that resembled intricate embroidery and diamond-encrusted lace. Millegraining was a new decorative technique that was born in this era and is a hallmark of Edwardian jewelry.
You might also hear jewelry from this period in time called Belle Epoque, which referred more generally to jewelry movements in the rest of Europe.