ART DECO & Transitional Jewelry, Art Deco Jewelry was a style popular from the mid 1910, until the mid 1920's This jewelry style originated in Paris, France. Art Deco Jewelry is characterized by geometric lines and angles, with very few curves.
The jewelry in this movement eventually became bolder and evolved into Art Moderne, now called Retro Jewelry.
Transitional Art Deco Jewelry is the movement from Art Nouveau to Art Deco design.
So we move from Art Nouveau to Transitional Art Deco, to Art Deco, then Art Moderne or Retro.