Consider x. In math, you solve for it. In fashion, the X factor solves your outfit.Get proof with Nido, a new line of geometric jewelry from Argentina-born, Brooklyn-based artist Cecilia Elguero.Made from sustainable porcelain, the squared-off rings and three-sided amulets are inspired by an ancient belief that certain shapes hold mysterious powers. To complement the raw texture of the clay, Elguero — a Parsons professor — finishes each piece with a metallic or smooth glaze.Inverted triangle pendants for your neck come in two sizes and base colors. We prefer white topped with gold or gunmetal, but the larger matte black version is equally powerful. The cubed rings’ asymmetric details (one-sided grooves, rounded divots, sloping edges) keep them from being too calculated. Our favorite piece, a ring that looks like a gold-rimmed bouquet of mini Q-tips (pictured), completely breaks the formula.Or should we say ex-formula?Available at Mary Meyer, 56 Bogart Street, at Harrison Place, Bushwick (510-703-8164 or marymeyerclothing.com), Life:Curated, 186 Grand Street, between Bedford and Driggs Avenues, Williamsburg (347-689-9143 or life-curated.com); online at nidodesuenos.com, $80-$160.Photo: Courtesy of NidoWant more local gems? Follow DailyCandy New York on Twitter.