Will a Fake Diamond Sink in Water?

Diamonds are considered precious and valuable stones, so it’s no surprise that people try to imitate them or sell fakes. However, distinguishing a real diamond from a fake one can be quite tricky, especially if you don’t have the knowledge or equipment to do it.

One common myth about diamonds is that they will always sink in water, while fake ones will float. But is this really true? In this article, we’ll explore this myth and give you the answers you need.

Diamond’s Density

Diamonds have a density of 3.5 g/cm^3, which indicates that they are denser than water, with a density of 1 g/cm^3. Therefore, a real diamond will sink to the bottom of a container filled with water.

In contrast, a fake diamond may have a different density, causing it to float rather than sink. This basic principle of the characteristic density of diamonds and water is what many people use to determine if the diamond is real or fake.

The Science Behind Diamonds and Water

To understand whether a diamond will sink or float in water, we need to understand its properties and the science behind it. A diamond is a dense and hard mineral made of carbon, which makes it heavy and resistant to scratches. However, diamonds have surface pores or imperfections that can trap air and affect their density.

When you place a diamond in water, the water’s density causes it to create an upward buoyancy force that opposes its weight. If the buoyancy force is stronger than the diamond’s weight, it will float. If the diamond’s weight is greater than the buoyancy force, it will sink to the bottom.

Characteristics of fake diamonds

Fake diamonds are commonly made of various materials that are cheaper than natural diamonds. Materials like cubic zirconia, moissanite, and glass are commonly used to make fake diamonds. These materials have different densities from natural diamonds, and thus, a fake diamond’s density will be different from that of a real diamond. It, therefore, follows that a fake diamond may float in water.

Will a Fake Diamond Sink in Water
Will a Fake Diamond Sink in Water

Why Some Fake Diamonds Float in Water

Now that we know the science behind it, let’s talk about fake diamonds. Fake diamonds, also known as diamond simulants, are materials that imitate the appearance of real diamonds. While these materials may look like diamonds, they have different physical properties that affect their buoyancy in water.

For example, cubic zirconia and moissanite are less dense than diamonds, which means they create less upward buoyancy force and are more likely to float. Glass, on the other hand, is denser than diamonds, but it may contain air bubbles or other imperfections that affect its density and cause it to float.

When a Fake Diamond Might Sink in Water

While fake diamonds are more likely to float in water, there are some cases where a fake diamond might sink. For example, some fake diamonds may contain materials that are denser than water, such as lead or tungsten.

These materials can increase the diamond’s weight and overcome the buoyancy force, causing it to sink. Some fake diamonds may have fewer surface imperfections or a higher density than real diamonds, which can make them more likely to sink. However, these are rare cases, and most fake diamonds will float in water.

Other Ways to Identify Fake Diamonds

While the water test may not always be accurate, there are other ways to identify fake diamonds. One of the most reliable methods is to get a professional gemologist to examine it. They have specialized equipment and knowledge that can distinguish real diamonds from fake ones.

You can also look for specific visual clues, such as an unusual rainbow or sparkling effect, which may indicate that the diamond is not real. Finally, you can compare the diamond’s weight, size, and clarity with known standards to determine its authenticity.


So, does a fake diamond sink in water? The answer is not always. While diamonds are more likely to sink due to their density and imperfections, some fake diamonds can sink too, depending on their materials and density. The water test alone is not a reliable method to determine a diamond’s authenticity, and you should always seek a professional opinion or rely on other methods to identify real diamonds.

Leave a Reply

Your email address will not be published. Required fields are marked *