March 19

What Does a Natural Diamond Look Like? | How Various Features Are Tested


Author: David Kopelman

Key Takeaways

  • You can use different methods to identify a raw diamond, including scratch test, thermal absorption test, specific gravity test, and hardness test.
  • A raw diamond doesn’t look like the polished diamond you’re used to.
  • Doing more tests to identify rough diamonds provides the best results.
  • Take your raw diamonds to a professional if you want to be sure whether they are real or fake.

What Does a Natural Diamond Look Like?

What comes to your mind when you hear about a raw diamond? This term is mentioned when talking about a natural diamond and sometimes its artificial counterpart. To help you understand the appearance of a natural diamond, I will discuss what it is and how it looks.

As you already know, refining a rough diamond involves a number of tasks. No diamond formed under the earth's surface is beautiful, and each piece comes in a rough and ugly shape. So what is a rough diamond? What are the different types available? What are the most famous raw uncut diamonds? Let’s dive in!

Raw diamonds

What is a Raw Diamond?

Rough diamonds are simply uncut and unpolished gemstones. When still in their original states, most diamonds look like pale-colored glasses. They usually have an oily appearance and do not sparkle. Additionally, a raw diamond exhibits a brownish or yellowish tint.

What Does Gem Quality in Rough Diamonds Mean?

Gem-quality diamonds are raw uncut diamonds that professionals use to make jewelry. They come in various shapes, sizes, designs, and cuts. On the other hand, industrial-quality diamonds have four primary uses.

Industry-quality diamonds are used for cutting, which involves the installation of diamonds into cutting tools to improve their cutting capacity. They’re also used for drilling to find other gemstones and minerals like gas and oil.

Famous Rough Diamonds

As an active spectator, you rarely see anything other than cut and polished diamonds. Also, this applies to the most famous uncut diamonds ever found, including the Taylor-Burton diamond, Tiffany Yellow diamond, Cullinan diamond, and Sergio diamond. Originally weighing 3106.75 carats, Cullinan remains to be the largest rough diamond ever mined in the world.

Cullinan diamond on the dark background

Tips for Identifying Raw Diamonds?

Diamonds are categorized as either cut and polished or uncut and unpolished. Uncut and unpolished diamonds are referred to as raw or rough diamonds. If you find a stone that looks like an uncut diamond, you can do a quick visual inspection to differentiate it from any other mineral. After identifying the diamond's shape, use three or four of these tests to determine if it is a rough diamond or not.

Focus on the Gravity

One thing that differentiates real diamonds from other minerals is their specific gravity. The average range of gravity is between 3.5 and 3.56 g/ml. To find the specific gravity of your suspected diamond, identify its weight, find a normal-sized drinking glass and fill it with water.

Place the drinking glass filled with water on a scale and submerge your gemstone using a string and ensure it doesn’t reach the glass base. Collect the reading and divide the stone's weight with the weight when submerged. If the outcome is close to 3.5, chances are you have a raw diamond.

Use the UV Light Test

Place your suspected diamond under ultraviolet light and observe the results. A real diamond will exhibit a blue glow, however, some raw diamonds don’t glow under ultraviolet light. That means you should try to use a diamond tester or scratch corundum to identify if it’s a real diamond.

Testing the diamonds with UV light

Test for Thermal Absorption

If you don’t have a diamond tester, you can buy one online or visit an expert. Once you have a diamond tester, press its tip against each individual diamond, and if it lights up and makes a unique sound, then rough diamonds are found.

Test Hardness

A hardness test can also help you to identify rough diamonds and you can do that by scratching glass. Most minerals scratch glass that has a hardness of 5.5 according to Mohs scale, so never identify rough diamonds using any other hardness test apart from scratching corundum.

With all rubies and sapphires, corundum has a hardness of 9 on the scale. Natural diamonds are extremely rare since they're formed from strong materials that take millions of years to mature. However, other minerals like moissanite and cubic zirconia are also scratch-resistant and durable.

Look at the Rough Diamond Through a Loupe

Jewelers use a special magnifying glass known as a loupe when it comes to differentiating diamond types from other stones. Put your rough diamond under the loupe and look for any rounded edges with small indented triangles. A coat of vaseline over your rough diamond is also a sign of the real deal.

Crystal Form and Fracture

When you look at a suspect diamond from the top, with any point of the crystal aimed at the eye, and you see four sides, chances are you can have a great diamond trade. In terms of fracture, it’s true that diamonds break.

In most cases, they cleave, creating smooth and flat surfaces. Other minerals, such as quartz and glass, create conchoidal surfaces when they fracture, meaning any signs of such surfaces indicate that your diamond isn’t real.

Rough diamonds and the loupe

Engagement Rings with Rough Diamonds

Rough diamonds from respected jewelers and online retailers can be trusted for their high quality and value. These diamonds are Kimberly certified, meaning you can use them on your diamond engagement ring.

However, you need to address certain considerations in terms of designs and settings since they retain their initial appearance and shape. Prong settings offer a perfect way of displaying raw diamonds.

Uses of Raw Diamonds

Many experts in the jewelry industry use rough diamonds to make jewelry. Additionally, they sell them as ornaments without cutting and polishing them. Raw diamonds are also used in various industrial processes, including cutting and drilling.

Different Types of Raw Diamonds

There are two types of raw diamonds, which include natural raw diamonds and lab raw diamonds. While natural raw diamonds are mined from beneath the surface of the earth, lab diamonds are man-made and undergo lab processes. Raw lab diamonds aren't fake since they have the same features as the real ones. Lab diamonds are affordable, free from any ethical issues, and friendly to nature.

Rough diamond rings and earrings

Final Thoughts

The chances of finding a real uncut diamond are very low. Even if you've found a real uncut diamond and purchased one of the best portable diamond testers to verify, no individual will trust you.

The only way you'll convince someone it's a real diamond is to ensure you have a certificate from the Gemological Institute of America. They’ll test your raw diamond and provide you with a valid certificate, positively identifying it as natural and real. They’ll also return your diamond unharmed.

FAQs about Raw Uncut Diamonds

What do Raw Diamonds Look Like When Found?

Raw diamonds are untouched and aren’t polished. They’re still in their original state.

How Do You Identify Natural Diamonds?

You can identify suspected diamonds through high profile weighing, electricity conductivity, sparkle test, fog test, specific density, and use of thermal conductivity. Additional methods are the entire crystal form and fracture test.

How Can You Identify a Raw Diamond at Home?

The methods you can use to identify a raw diamond at home are fog test, scratch test, fracture, and portable diamond testers. Seek help from experts if you are unable to test it at home.

What Are the Different Types of Raw Diamonds?

The different types of raw diamonds are natural and lab-grown. Lab-grown diamonds are the cheapest.

About the Author:

David Kopelman

In every article I write, I share my experience as a GIA Graduated Gemologist so that you learn everything about diamonds and other precious stones.

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