Chain: 20 inches of ribbon
Pendant: 0.5-0.75x1.5 inches.
Material: unknown metal content, most likely dyed howlite stone.
Picture is an example, each one is very similar.
Beautiful and unique handmade Tibetan jewelry made in Nepal and Tibet by Tibetan refugees.
Repoussé refer to a metalworking technique in which a malleable metal is shaped by hammering from the reverse side to create a design in low relief.