If the person you are buying for wears jewelry every day, 14kt is a practical choice since it's harder and more abrasion-resistant than 18kt. If the piece is for occasions and the richest gold color matters most, 18kt may be best.
Style Notes
White gold has been prominent in fine jewelry for over a century with no signs of fading. That's not a trend. That's a track record. For pieces meant to last, the stylistic staying power is part of the argument.
Made With Purpose
Feed the jump ring into the open gate, release the lever, and the spring pulls the gate closed around it. At rest, the ring is fully enclosed. You can feel the resistance if you try to pull it free, because the clasp has sealed the ring completely.