Most of us have looked at the sparkling necklace of a relative or friend and wondered if it was made of real diamonds or plain stones. Some of us even have hand-me-down jewellery from our grandmothers, but we may not have the time to take it to a gemologist to get it verified. How do we tell if a white stone is a real diamond or simply sparkling glass? Sometimes the glittery and lustrous stones can turn out to be similar to cubic zirconia or moissanite, which look like diamonds. To tell a fake diamond from a real one, there are some home tests that you can put the stones through. We list down some of these tips for you to try out.
Easy Home Tests to Identify If Your Diamond is Real or Fake
It may be prudent to know how to identify a real diamond and tell it apart from other gemstones. Here are some tests that you can do at home:
1. Look at the Stone through a Loupe
A loupe is a type of magnifying glass used by jewellers. When looking at a stone through a loupe, here are some things to consider:
- A real diamond will have imperfections because it is formed naturally whereas a fake stone will look perfect. But caution is to be shown here because there are lab-grown diamonds which may look perfect too.
- A diamond has sharp edges while a regular stone would have rounded edges..
2. Rub Sandpaper against the Stone
Use a piece of sandpaper to rub the surface of the stone. Sandpaper, being abrasive, will create some scratch on the stone if it is moissanite or cubic zirconia. Whereas if it’s a diamond, it will remain unaffected as it is one of the hardest materials known to man.
3. Water Test
If you have an unmounted stone, the water test works well for you. Fill 3/4th of a glass with water and drop the stone into it. A stone that sinks to the bottom is a diamond while one that floats on the surface of the water is fake. This is because diamonds have a very high density and hence sink immediately.
4. Fog Test
Hold the gem out in front of you and breathe warm air onto its surface the way you would do to clean a glass surface. If the layer of moisture fades immediately, then the stone is a diamond. This is because diamond conducts heat efficiently and so it disperses the heat immediately too. Any other stone will reflect a coat of moisture for much longer.
5. Reflectivity of the Stone
Hold your stone under the light and observe how the light is reflected. Diamond reflects light uniquely. The inside of the diamond will reflect pure white or grey light known as ‘brilliance’. The outside of the diamond will reflect coloured light in a beautiful way called ‘fire’. As opposed to this, ordinary stones reflect a rainbow coloured light from the inside and are not as brilliant as the diamond.
Diamonds sparkle largely due to their ability to bend light and reflect it. When light hits a diamond on its angled surface, this light is bounced and refracted by the flat surface of the diamond. You can test the refraction of a stone by placing its flat side on a newspaper and looking through the pointed side, try reading the lettering. If the letters are visible even vaguely, the stone is a fake. High refraction of a diamond will ensure that light is scattered in different directions and not a straight line. It means that you cannot see through a diamond onto the other side. This test works only if you have a loose stone and not if it is in a setting.
7. Heat Test
Again, this test works if you have a loose stone. Hold it between forceps or tongs and heat it under direct fire for about 40 seconds. Immediately drop it into cold water. Gemstones cannot withstand the pressure of such a sudden change in temperature and will shatter immediately. A diamond is a very strong substance and is not affected much by the temperature change. It remains unscathed because of its ability to dissipate heat quickly.
8. Setting and Mount on Metal
If your stone is already mounted on metal, it is appropriate for you to check the setting and the metal thoroughly. If the setting reflects poor workmanship, then the stone is definitely not a diamond. Look at the etching on the mounting. If you notice markings like 18K, 22K, or PT, it indicates that the metal used is gold or platinum. Real diamonds will definitely be set in quality metal such as these. If the mount is gold-plated or silver, you can be assured that your stone isn’t a real diamond. If you also notice markings of CZ, it indicates that the stone is cubic zirconia and not a diamond.
Here are some most-asked queries about diamonds:
1. Is It True That Real Diamonds Sparkle Rainbow Colours?
In truth, a diamond does not sparkle rainbow colours. A diamond, because of high refraction, bends and reflects light in all directions. Due to this, white light is reflected as pure white or light grey on the inside of a diamond. The rainbow colours will only be reflected on other surfaces that are outside the diamond. For example, if your diamond is set in gold, the rainbow sparkle is a reflection of the coloured light on the gold. It doesn’t come from the inside of the diamond.
2. Can a Real Diamond Cut Glass?
Diamonds can definitely scratch or cut the surface of glass with ease. This is because diamonds are known to be one of the strongest materials on Earth. They are about 40 times harder than glass and rate 10 on the ‘Mohs scale’ of hardness while glass rates a 6.
There are other methods like the UV light test which show that some diamonds give off a blue glow in UV light whereas other stones will have green, grey, or other coloured glows. A lot of the above-mentioned tests work better if you have loose stones to identify. With each case, there should be prudence and caution applied because you risk losing your fake stone with some of these tests. If you don’t mind destroying a fake stone, then the shatter test or the sandpaper ones are effective methods of confirming the identity of your stone.
An important thing to remember is that none of these tests is ‘set in stone’ and the best way for you to categorise your stone would be by taking it to an authorised jeweller. Professional jewellery businesses have advanced tools like thermal conductivity probes and accurate high profile weighing scales to determine the correct value of a stone. They also have a keen eye for spotting the differences between moissanite, white sapphire, topaz, cubic zirconia and a real diamond. If you are unsure, seek the expertise of a professional to value your gems.