glass, pearly, iridescent, metal, bronze or brass, 
seed beads have long been used for embroidery (the very fine 24/0 seed beads are now being replaced by 15/0 - approx. 1 mm).Rocaille pearls include 
Japanese pearls (regular and generally in size 15/0), 
charlottes (in size 13/0) with facets for added sparkle, and 
Delica, perfectly regular cylindrical Japanese pearls ideal for pearl weaving (Delica being the best-known brand name) and available in many surface treatments (iridescent, matte, satin, AB or lined...).
 
- Cloisonné pearls are made of copper and covered with baked enamel, like stained glass. Commonly found pearls are made in China.