There are several ways.
When you see a stone which you would like to determine if it is a diamond, you can do a quick visual inspection. There are certain characteristics of a diamond which separates it from other gemstones.
Observe the top side of the crystal and also count the sides. Diamonds should be cubic in shape while other stones like quartz (which look similar to a diamond) have a hexagonal shape.
If you observe that the crystal has 4 sides, there is a big chance it is a diamond. A stone with 6 sides would mean it is most likely a quartz crystal.
But don’t stop here. It is advised to use more methods to reduce the chances that you are wrong.
Be more precise in your testing for a diamond if it is real by using a piece of corundum.
A corundum is also another type of crystal that is lesser in hardness than a diamond. You can buy an affordable piece of corundum or a mineral testing kit that has corundum in it.
With the corundum, scrape the crystal against it. The corundum should be held firmly on a sturdy surface when doing the scraping process.
If there is a visible scratch that is produced, the crystal is most likely a diamond. If there is no scratch trace whatsoever, then it is a different type of mineral.
They can be bought online. This is an alternative method to the scratch test or to be more accurate, use the two methods.
The principle behind the diamond tester is that it uses both thermal and electric conductivity for diamond analysis.
Before use, the diamond tester should have a full battery charge which you will know when the green light is on. Now, press the tip of the diamond tester to the rock.
When a noise is made and the lights brighten up, then the crystal is a diamond. If the machine is quiet and the light doesn’t react, then it’s a different kind of gemstone.
As per experience, the more expensive diamond testing models are more accurate than cheaper ones. Also, customer reviews could help you decide on which brand and unit to purchase.
The use of an Electric Scale can help you determine the density of the crystal you are testing. After all the testing has been done with the use of this device, and the result is that the rock tested has a density between 3.5 to 3.53 grams per cubic centimeter, in most likelihood, you have a diamond in your hands. If it is less than this measurement, it is a different gemstone.
Some electric scales have more accuracy than other brands. Choose one which have at least 2 to 3 decimal places after the whole number.
This is the process using an electric scale.
Fill a paper or plastic cup with enough water that can fully submerge your crystal that will be experimented with. You can also use Tupperware or bowl that is made of plastic and lightweight.
Now, place the cup with water onto the electric scale. You have to make sure that the container is centered on the scale and not on the edges. Zero out the scale by hitting tare.
Zeroing out the electric scale will help you know the specific gravity of the crystal without the inclusion of the weight of the water and the cup.
Next, wrap a paper clip around the tested crystal in such a way that it will be suspended in the water without it sinking to the container’s button or touching the sides of the container.
Thoroughly unbend a paper clip and wrap one of its ends tightly around the widest section of the stone. Suspend the stone into the water by holding on to the other end of the paper clip.
Sink the crystal into the water and now record its weight. Again, make sure sure it doesn’t touch the bottom or the edges of the container because the reading will be inaccurate. The weight of the paper clip will be a negligible issue.
If the stone, outside the container, weighs 13 grams and its weight, while suspended is 5 grams (13/5), you would get a specific gravity of 2.6. This is the approximate density of quartz, so it is not a diamond.
Your stone should have a specific gravity in the range of 3.5 to 3.53 grams per cubic centimeter to qualify as a diamond.
Get to know if your crystal was extracted in an area where there are Kimberlite pipes. These are igneous stones that were evolved from molten magma. They are usually found under the soil surface.
Microscope or 10x Loupe
These devices enable you to examine a stone in a much magnified way.
When you place the stone under this device, look for rounded edges with small indented triangles. Or they can have parallelograms or squares that are rotated.
Do all or some of the above methods, together with the professional evaluation of an expert jeweler. Visit Rare Carat to get unbiased and quality opinion about gemstones of all types.