One sure way to test the genuineness of a diamond is by means of what jewelers call the water test. An imitation stone never shines as brilliantly as a real one, but the contrast is not always easy to detect just by ordinary viewing. Jewelers know that placing a genuine diamond and an imitation side by side in water will reveal the differences. The real one continues to sparkle brilliantly underwater, whereas the fake one loses practically all its sparkle.
