The jewelry designer Todd Reed, known for his use of diamonds in their natural, rough form, this month opened a three-level, 6,000-square-foot store—with a workshop for men’s jewelry and accessories—in Venice Beach, Calif.

Known for using rough diamonds that appear more like tumbled rocks than sparkling stones, Reed has established a loyal following of men and women for his edgy, artistic style. The new store presents his wide breadth of men’s jewelry ($1,000 to $20,000), including pieces in textured sterli…