How to Identify Raw Diamonds – Techniques for Recognizing Uncut Gemstones

How to Identify Raw Diamonds – Techniques for Recognizing Uncut Gemstones

As a gemologist, I am often asked about the process of identifying raw diamonds and uncut gemstones. Recognizing raw diamonds can be quite challenging, as they often bear little resemblance to the dazzling diamonds we are accustomed to seeing in jewelry. In this guide, I will share with you techniques for identifying raw diamonds and spotting uncut gemstones in their natural state. By the end of this post, you will have a better understanding of the characteristics and features that can help you differentiate between a raw diamond and other similar-looking minerals. Let’s dive in and explore the fascinating world of raw diamonds together.

Key Takeaways:

  • Understanding Diamond Characteristics: Knowing the key features of raw diamonds, such as their shape, color, and luster, is essential in identifying uncut gemstones.
  • Quality of Light Reflection: The way raw diamonds reflect light can help distinguish them from other minerals, as they have a unique sparkle and brilliance due to their crystal structure.
  • Scratch Test: Conducting a scratch test using a piece of glass can help determine the hardness of a raw diamond, as they are one of the hardest materials on Earth.
  • Consulting a Professional: When unsure about the authenticity of a raw diamond, seeking the expertise of a gemologist or diamond appraiser can provide valuable insights and confirmation.
  • Use of Specialized Tools: Utilizing tools such as a loupe or diamond tester can aid in the identification of raw diamonds by examining their clarity and thermal conductivity.

Types of Raw Diamonds

Your ability to identify raw diamonds depends on recognizing the different types of uncut gemstones. By understanding the unique characteristics of each type, you can better distinguish between them and make a more accurate assessment of their potential value. Here are the main types of raw diamonds you’ll come across and how to identify them:

Type of Raw Diamond Key Characteristics
Alluvial Deposits
Yellow Diamonds
Blue Diamonds


Kimberlite is a type of rock known for containing diamonds and other precious minerals. It is typically found in volcanic pipes or dikes and is characterized by its blue-grey color and coarse texture. When searching for raw diamonds in kimberlite, I look for visible crystals and a rough, uneven surface, which can indicate the presence of uncut gemstones. Kimberlite is a primary source of diamonds and can often be found in areas with a history of diamond mining.


Lamproite is another type of volcanic rock that can contain diamonds. It is similar in appearance to kimberlite but is typically a darker shade of grey or green. When examining lamproite for raw diamonds, I pay close attention to its mineral composition and overall texture. Lamproite is less common than kimberlite but can still yield valuable uncut gemstones when properly identified.

Tips for Identifying Raw Diamonds

While identifying raw diamonds can be challenging, there are some techniques that can help you recognize uncut gemstones. Here are some tips to help you identify raw diamonds:

  • Examine the diamond’s shape and texture
  • Check for impurities and imperfections
  • Perform scratch testing
  • Use UV light testing

Recognizing raw diamonds takes practice and patience, but with these tips, you can improve your ability to identify uncut gemstones.

Scratch testing

One method for identifying raw diamonds is scratch testing. Diamonds are the hardest natural substance on Earth, so they should not be easily scratched. You can perform a scratch test by using a piece of corundum, which has a hardness rating of 9 on the Mohs scale. If the diamond is uncut, it should not be scratched by the corundum.

UV light testing

Another technique for identifying raw diamonds is UV light testing. Most diamonds emit a blue fluorescence under UV light. You can use a UV light source to observe the reaction of the diamond. If it emits a blue glow, it is likely a diamond. However, it is important to note that not all diamonds exhibit this fluorescence, so UV light testing should be used in conjunction with other identification methods.

Step-by-Step Techniques for Recognizing Uncut Gemstones

To accurately identify raw diamonds, it is important to follow specific techniques that have been developed over time. The following table outlines several methods for recognizing uncut gemstones:

Technique Description
Visual inspection Examine the physical characteristics of the stone, such as color, luster, and shape.
Specific gravity testing Measure the density of the stone to determine if it matches the characteristics of a diamond.

Visual inspection

When visually inspecting a raw diamond, look for rough, unpolished surfaces and sharp, distinct edges. Raw diamonds often have a dull, waxy luster, which sets them apart from other stones. Additionally, the color of the diamond can provide important clues about its authenticity. A true raw diamond may have a slight yellow or brown tinge due to the presence of nitrogen.

Specific gravity testing

To perform a specific gravity test, weigh the stone in air and then in water to determine its density. A diamond will typically have a specific gravity of about 3.52, which is higher than most other gemstones. The presence of air bubbles when the stone is submerged in water can also indicate that it is a diamond, as diamonds are hydrophobic and repel water.

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Factors to Consider When Identifying Raw Diamonds

For identifying raw diamonds, there are several important factors to consider. These factors can help you determine whether the gemstone you have is actually a raw diamond. Some of the key factors to consider include color, transparency, and shape. After examining these factors, you can more confidently identify whether a gemstone is a raw diamond or not.

  • Color
  • Transparency
  • Shape


When it comes to identifying raw diamonds, color is a crucial factor to consider. Raw diamonds can come in a variety of colors, but the most common are white and various shades of yellow. However, the presence of other colors such as blue, green, or pink can also indicate the presence of impurities in the diamond. Overall, a pure white or yellow hue is typically a positive sign of a raw diamond.


In addition to color, the transparency of a raw diamond is another important factor to consider. Raw diamonds are known for their exceptional transparency, allowing light to pass through with little obstruction. This transparency is what gives diamonds their distinct sparkle and brilliance. If a gemstone appears cloudy or opaque, it is unlikely to be a raw diamond.

Pros and Cons of Identifying Raw Diamonds

Now that we’ve discussed the various techniques for recognizing uncut gemstones, it’s important to weigh the pros and cons of identifying raw diamonds. Identifying and working with raw diamonds has its advantages and disadvantages, and it’s crucial to consider these factors before delving into the world of uncut gemstones.


One of the main benefits of identifying raw diamonds is the potential for significant value. Raw diamonds can be more valuable than cut and polished stones, particularly if they possess unique characteristics such as color or clarity. Additionally, being able to identify raw diamonds allows for a deeper understanding and appreciation of these precious gemstones. It can also be a fulfilling and rewarding experience to discover and work with raw diamonds, knowing that you have uncovered something truly special.


However, it’s important to recognize the potential drawbacks of identifying raw diamonds. One of the main challenges is the difficulty in accurately assessing the quality and value of uncut gemstones. Without the expertise and equipment of a professional gemologist, it can be challenging to determine the true worth of a raw diamond. Additionally, there is a level of risk involved in investing time and resources into identifying and working with raw diamonds, as there is no guarantee of finding a valuable specimen. It’s crucial to approach this process with caution and thorough research to mitigate these risks.

It’s essential to carefully weigh the pros and cons of identifying raw diamonds before embarking on this journey. While there are potential rewards in discovering and working with these precious gemstones, there are also significant challenges and risks to consider. Ultimately, a thoughtful and informed approach is key to successfully navigating the world of uncut diamonds.

How to Identify Raw Diamonds – Techniques for Recognizing Uncut Gemstones

Conclusively, identifying raw diamonds can be a challenging but rewarding task. By utilizing the techniques discussed in this article, you can begin to recognize the distinct characteristics of uncut gemstones. Remember to examine the color, clarity, and shape of the diamond to determine its authenticity. Additionally, seeking the help of a professional jeweler or gemologist can provide further insight and expertise in identifying raw diamonds. With a keen eye and knowledge of these techniques, you can confidently identify raw diamonds and appreciate the beauty and value of these precious gemstones.


Q: What are the characteristics of raw diamonds?

A: Raw diamonds typically have a glassy appearance, with a white, transparent, or oily texture. They may appear rough, irregular, and unpolished, and often have a dull or greasy luster.

Q: How can I distinguish a raw diamond from other minerals?

A: Raw diamonds have a high refractive index, which means they sparkle and reflect light more brightly than other minerals. Additionally, their hardness makes them resistant to scratching and allows them to scratch glass, making them stand out from other stones.

Q: What are the tools needed to identify raw diamonds?

A: To identify raw diamonds, you may need a loupe or magnifying glass to inspect the stone for inclusions, color, and crystal structure. Additionally, a diamond tester or thermal conductivity probe can help confirm the authenticity of the diamond.

Q: Are there any specific tests to confirm if a stone is a raw diamond?

A: One common test is the fog test, where a real diamond disperses heat quickly, so fog on the stone should disappear more rapidly than on a fake diamond. Another test is the water test, where a real diamond will sink in water due to its high density, while most fakes will float.

Q: What are the key features to look for when identifying raw diamonds?

A: When identifying raw diamonds, pay attention to the stone’s color, clarity, and shape. Inclusions, such as tiny minerals, crystals, or fractures inside the stone, are also important to scrutinize. Additionally, examine the stone’s surface for any unusual blemishes or irregularities.