Fake diamonds have become increasingly realistic and diamond buyers may worry that they don't have the real thing. Unscrupulous jewellery appraisers may lie about the authenticity of a diamond or may even change out a real diamond for a fake one. If you're concerned that your diamond and silver band may not be real, a few simple tests can give you the truth.
Place the diamond stone over newsprint. If you can clearly read the newsprint through the diamond, it is likely a fake. Real diamonds scatter light and make newspaper impossible to read. Very small or shallow-cut diamonds, however, may still be transparent, so if your diamond is a thin one, the newspaper test may not give you the right answer.
Put the stone under a fluorescent light. Most diamonds will give off a bluish reflection. Moissanite, which is a diamond look-a-like, will reflect green, grey, or yellow. If there is no reflection, this does not necessarily mean it's not a diamond, because some higher quality stones will not reflect colour. A bluish reflection, however, does definitively verify that it is a diamond.
Check the stamp on the ring. If you're not sure if the metal used in your ring is real, silver and gold will both be stamped on the inside of the band.
Fog the stone with your mouth. Place the ring in front of your mouth and fog it with your breath the same way you would fog a mirror. If the fog sticks to the stone for more than a few seconds, it's a fake. Real diamonds quickly disperse heat and thus won't stay fogged for long.
Take your ring to an appraiser. The best way to find out if your ring is real and to learn its value is to consult an expert. Have the appraiser appraise the stone in front of you. Most appraisers will charge £30 or so to verify the authenticity of your stone.