Known for designing with black diamonds in his namesake jewelry line, Azature Pogosian has added the title of creative director at Bavna, a Los Angeles-based jeweler founded in 2011. For Bavna, he’s working more with paraiba tourmaline and architectural shapes, and will be introducing a capsule collection, Azature for Bavna, this fall. With the improving economy, he said, Neiman Marcus and Saks Fifth Avenue have increased their orders — shoppers are once again buying jewelry priced more than $20,000. One paraiba cocktail ring goes for $64,900. Bavna’s annual sales are more than $5 million.