What JCK’s Emili Vesilind is loving this month“I’m bewitched by slightly off-kilter color combinations and classic designs made modern with of-the-moment gems.”  —Senior editor Emili Vesilind     The playful mash-up of stones—sapphires, emeralds, opals, tourmalines, and diamonds—puts a cool-girl spin on a vintage-feeling design. (Irene Neuwirth, price on request, ireneneuwirth.com)   Circles, squares, rectangles, and triangles live in perfect harmony in this feat of geometric gemology, comprising emeralds, pink sapphires, tsavorites, and a boulder opal. (Brooke Gregson, $12,655, brookegregson.com)   I love how artfully—and jauntily—the stacks were built in these boulder opal earrings. (Kimberly McDonald, $14,000, kimberlymcdonald.com)   This lunar pendant necklace with graduated rubies is both ultra-g