Crooks advertise the “carat total weight” of diamonds in a ring, but avoid mention the individual weight of the center piece.

How is that important? A big diamond is worth much more than the 7 small ones around it that equal it in weight. If you are considering buying, always ask for a written offer, giving the quality and weight of the centerpiece itself. If they try to avoid doing that, go to the next shop.

Another method of tricking the customer is by adjusting the lighting. If the stone shown has yellowish aspect, the seller will show it to you under a bulb with a strong blue component – so that it will look whiter. The bulb may also have ultraviolet features, which means the diamonds will reflect more blue.

Another trick you should be aware of is the “blue paint”. That means some sellers paint the lowest tip of the diamond (the culet) with an almost imperceptible spot of blue which does wonders when the diamond is reflected under a specific light. The colors will look so vibrant that the diamond will actually seem to be the best of all you’ve seen so far.

How to avoid: ask the seller to clean the diamond in front of you, with an ultrasonic substance. Bottom line is - if you decide to buy a diamond, you should really learn more about the industry before you do it. One last thing, always ask to see the stone in a natural light, because that’s where everybody will see it anyway.