Signet Jewelers has acquired Rocksbox, a jewelry rental subscription service, for an undisclosed price. The parent company of Kay Jewelers, Jared, Zales and other mall-based chains is looking to reach more younger female consumers with the Rocksbox acquisition. Signet’s core business caters primarily to older men. “Jewelry rental is complementary to our traditional offerings,” said Virginia Drosos, Signet CEO.