Back to StackThe stackable craze continues. During jewelry week, manufacturers debuted new lines of stacking rings in both bridal—smaller diamond engagement rings as well as bands—and in fashion.For Plano, Texas–based Sylvie Collection, a new Petite line of complete diamond engagement rings features small cuts—0.30 ct. to 0.90 ct.—of fancy yellow diamonds in 14k and 18k gold. (Platinum is available on request.) “Customers have been asking us for small centers,” said designer Sylvie Levine. Many start in the $1,000 retail range, and when ordered in 14k gold, retailers can afford to have assortments of live centers in mountings in-store and “ready to go,” adds Levine.Tiny stacking rings in 18k gold with 0.11 ct. t.w. black or champagne diamond pavé; starting at $770; Syna, Fort Lee, N.J.; 201-585-2021; synajewels.comNew York City’s Cora is thinking similarly. In JCK’