How can you tell a fake diamond from a real one?
It is not always easy but here are some pointers that may help.
Firstly ensure you deal with a reputable dealer. It is the height of foolishness to 'buy' a diamond from a 'mate' or someone you know or one advertised in a newspaper perhaps. Also do not buy diamonds unseen. You certainly have no way of knowing if a diamond is real if you cannot yourself inspect it.
Ask the dealer if the stone you are looking at is a real diamond. He should be able to tell, if he cannot find one who can. This is not an area to make mistakes in. You can go further and ask if the stone is a genuine diamond, a cubic zirconia or moissanite.
Check the setting and the mount. A genuine diamond will usually be set in quality metal such as gold or silver. A Zirconia is cheaper than diamonds of course so an inferior setting may betray the stone. A real diamond has sharp edges also while a fake will have rounded edges.
Check for any scratches, nicks on the stone. A diamond is extremely unlikely to have any of these but a zirconia is nowhere near as hard so subject to wear and tear.
A fake diamond will show a rainbow effect if you look inside. A real diamond does not have that. If anything it will show more like a grey color.
There is another way to test quickly. Take the diamond and breathe on the surface. If it fogs up it is not a diamond. A diamond does not fog up when you breath on it because it does not retain the heat from your breath.
Just about all diamonds, naturally made, have imperfections. In fact this is often what gives particular diamonds their characteristics and how you can tell which diamond is which. Looking through a jewellers Loupe (A special eye glass for looking at diamonds closely) and there are absolutely no imperfections whatsoever, it is likely to be a zirconia or other artificial diamond. It is not a final test however as some diamonds grown in laboratories will have no imperfections so it is not a stand alone test and should be performed in conjunction with a battery of others such as are explained in this article.
Diamonds are the hardest known substance so you can also rub a diamond with sandpaper. If it scratches you know for sure it is not a diamond!
Any reputable jeweller will be able to tell a fake from a real diamond. You should ask the jeweller if you can look through their loupe yourself.
All diamonds should have a certificate from the Gemological Institute of America (GIA) or a similar reputable organisation. The GIA, the largest impartial diamond grading authority in the world, issues a grading report after it examines the diamond and details it specifications. In addition the stone should be appraised by an independent appraiser such as one associated with the American Society of Appraisers (ASA). The certificate should indicate the value and characteristics of the stone.
It is important therefore that in any diamond purchase you ensure you have a certificate and an official appraisal of the stone to establish its authenticity as a genuine diamond and also for any further sale or valuation as well as for insurance purposes.
Other stones often mistaken for diamonds are:
White topaz. This a tinted mineral usually with a brown, red or yellow tint but sometimes pale grey or even white or colourless. tinted yellow, red, brown, or pale gray, but can sometimes be white or appear colorless. Again they are not as hard as a diamond so scratches will give them away.
Sapphires come in a range of colors, not just blue and you can also get white sapphires. Again they are softer than diamonds and various tests will show this. Like Topaz they do not have the same brilliance as a diamond.
Just about everyone knows about Cubic Zirconium produced since 1976. This stones scratches very easily and has nowhere near the same 'fire' or brilliance of a diamond. Sometimes a zirconia is actually mounted in a good quality setting of 18 or more karat gold or platinum. In this case you definitely need to consult an experienced jeweller as it will be difficult to assess if the stone is a fake diamond or not.
The other material, moissanite, is even more difficult to tell from the real diamond. Moissanite is only worth one tenth the value of a diamond but is virtually indistinguishable and it takes a real expert with special equipment to be able to tell the difference. But you may be able to see the rainbow effect when looking through a jewellers loupe.
Laboratory grown diamonds are the closest to a natural diamond you can get. They do not have that individual quality of a diamond although technically perfect. The main advantage with lab grown diamonds is the price being around 20 to 30 percent cheaper than a naturlal diamond.