What Does A Raw Diamond Look Like?

If you live near a mining area or one that’s renowned for having crystal stones, it’s easy to find gems that resemble raw diamonds. In other cases, you may be an enthusiast seeking these precious stones at selected locations or prefer them on your jewelry instead of cut ones. Whatever the situation, it’s possible to come across crystals that, at first glance, resemble a diamond. And when you do, you may be tempted to celebrate that you’ve hit the big leagues.

But you may want to take a step back and fully analyze a crystal to be certain. The reality is that many stones may appear like real diamonds but turn out to be something entirely different and much less valuable. So, before you rush to the nearest jewelry store or pay for a stone, you’ll need to understand what a raw diamond looks like. And you’ll want to learn the properties to check for and the right tests to carry out to be certain you’ve found the real thing.

Raw Diamonds-The Origin

A raw diamond is a diamond in its purest, untouched form. This means the diamond’s original state when first mined from the earth. And such a stone will look like a quartz pebble worn by water erosion. But how the diamond got there in the first place is a different story that took place eras ago in the earth’s earliest years.

According to geological studies, diamonds were formed around 90 million to 3 billion years ago deep beneath the earth. And the crystals are a product of carbon compounds subjected to intense temperature and pressure below the ground. It’s stated that diamonds formed around 90 to 400 miles below the earth’s surface at a staggering temperature of 2100F. And they required a pressure that amounted to 45,000 times what’s experienced at sea level.

For diamonds to be created, carbon atoms were pressured to form incredibly tight bonds, which forced the compounds to create crystals. And these crystals developed to become diamonds- the hardest substance ever recorded in human history. These gems grew in volcanic areas, and the pressure that formed them forced the molten magma to push the stones closer to the surface eventually. And during volcanic eruptions, the stones were brought up to the surface, where they remained buried in layers beneath the earth until they were discovered and mined by man.

Most of the raw diamonds didn’t survive the extreme heat of the magma, but the ones that did were trapped in kimberlite rocks. And by water action, these rocks were weathered through erosion to release most of the stones, further carried by flowing water bodies. These stones were then deposited in alluvial regions next to rivers, streams, and beds of running water. And it’s from these surfaces around the earth humans realized they could mine the gems and use them for various purposes.

Most raw diamonds were extracted by processing about 250 tons of ore. And from such a massive amount, only one carat of a diamond is mostly found. Though all diamonds mined from kimberlite rocks and pipes are useful, only 20% to 30% of them are suitable for gemological purposes. Raw diamonds can be found in Russia and Australia, with the former being the number one site for such stones. But the most commonly mined regions for these gems include Angola, South Africa, Botswana, Congo DR, Sierra Leone, Namibia, and Zimbabwe.

The Popularity Of Raw Diamonds In Jewelry

While most diamonds we know today are cut before being used in jewelry, raw diamonds still have their place in the industry. And numerous stones have been found that still 3holds significant importance in human history. Examples of such raw diamonds are listed below;

  • Cullinan Diamond- This stone held the record as the largest diamond of gem quality and was named after Thomas Cullinan, the chairman of the mine where it was discovered. The stone weighed about 3106.75 carats upon its discovery. According to historical accounts, the stone took two years before it could gain enough interest to peak interested buyers. And today, it’s known as the parent of the Great Star of Africa, the largest clear-cut diamond worldwide.
  • Tiffany Diamond- The Tiffany Yellow holds the record of the largest yellow diamond ever discovered and weighs around 287.4 carats in its rough form. But after it was cut in cushion style, the final result was recorded at 128.54 carats, with 82 facets- 24 more than normal. The stone was named after Charles Tiffany in 1879 and was studied by his company gemologist George Kunz before it was cut.
  • Taylor Burton Diamond- While this stone may not share the incredibly large size of its counterparts, it makes up for its popularity. The Taylor Burton diamond gained fame when an actor, Richard Burton, bought it for his wife, Elizabeth Taylor, at $1 million in 1969. The stone originally weighed 241 carats before being cut to a pear shape of 69.42 carats by the reputable diamond dealer, Harry Winston.
  • Sergio Diamond-Though this stone isn’t as valuable as its expensive cousins, the Sergio diamond weighed a staggering 3,167 carats, making it one of the largest raw diamonds ever mined. But it was only fit for industrial use and was broken up for such purposes upon assessment.

Lab Raw Diamonds

While raw diamonds were originally found in the natural world, man has also figured out how to make them in the lab. Lab raw diamonds are created using the same processes and minerals as natural diamonds but in an artificial environment. Like natural raw diamonds, lab raw diamonds haven’t been cut or polished. And they’re identical to natural raw diamonds in physical structure, chemical properties, and geological attributes.

Lab raw diamonds also offer a more economical approach to producing diamonds as they’re not mined. As such, their cost of production is lower, and more of these crystals can be generated faster. Plus, they’re cheaper and considered more ethical, with some enthusiasts rating them as more ‘nature-friendly.’

How To Know A Raw Diamond?

If you’re in the market for raw diamonds, it helps to know how to identify them. The reason is that tons of other gems and stones share a similar physical and crystalline appearance with real diamonds and can pass as the real thing under light scrutiny. But it also helps to bear that the chances of coming across a raw uncut diamond are incredibly slim- around a billion to one. But if you do find a crystal and aren’t sure, look for these factors;

Form, Size, & Weight

A real raw diamond features a cubic or isometric form, meaning only four sides. They’re also known to form octahedral crystals measuring the same in every direction that surrounds the center. It’s easy to use this factor to differentiate a real diamond from quartz- a commonly confused crystal. Unlike diamonds, quartz develops hexagonal crystals mostly with one terminal end, except for Herkimer diamonds which produce two terminal ends.

Also, most raw diamonds found weigh around 2 grams, meaning the average stone discovered is less than 10 carats. Yes, some uniquely large diamonds have been recorded, but these are rare cases, and to date, stones of such massive sizes haven’t been seen. In contrast, quartz and other similar-looking gems can grow up to 4 grams and exceed 8mm in length. And the possibility of finding a diamond of such dimensions is nearly slim to none.

Thermal Absorption

An ideal way to know if a crystal is a raw diamond is by checking its thermal absorption rate. The reason is that diamonds excel best at absorbing heat, and this property can be analyzed using a special tool called a diamond tester. A diamond tester works on the principle that reads the specific rate at which heat dissipates in real diamonds. And it displays this measurement using light indicators that tell you if the level measured means you’re holding a diamond.

A typical diamond tester includes a metal prong that touches the gem to measure how quickly heat dissipates. A series of light indicators are lined on the tool’s body, with the level that proves a diamond marked. When the tester is turned on, the metal pin touches the diamond, sending heat through the stone. Then, the tester calculates how fast the heat is absorbed, and the indicator lights up at a level that determines whether the stone is a diamond or not.

Unfortunately, some crystals like moissanite share a close heat absorption semblance with diamonds; thus, the heat absorption test may not be one to be run alone. You’re advised to carry out as many confirmation tests as possible to be certain you have a raw diamond.

Electrical Conductivity

Diamonds have a unique electrical conductivity rate, and this property can also be examined in a gem to confirm if it’s one. And it’s considered one of the best singular tests to run if you’re confirming a raw diamond. Electrical conductivity tests work hand in hand with thermal absorption tests, so the best diamond testers combine both principles. First, the thermal absorption test is carried out, and after the result, an electrical charge is sent into the stone. Then, the indicator tells you the rate of conductivity and hints whether it’s for a diamond or moissanite.

Multi-testers are used when carrying out this test because they use the technology for both heat and electrical tests. And though they’re costlier than regular diamond testers, they’ll offer a more accurate result and give you the confirmation you need.


While the hardness test isn’t advised for cut diamonds, it’s a great way to test if a raw diamond is real. Real diamonds are considered the hardest minerals on earth and rank ten on the Moh’s Scale of Hardness- the highest mineral rating. No other gem or mineral can scratch its surface when rubbed, which is where the hardness test comes into play. And the procedure is simple; you’ll find another gem or crystal of a high Moh’s rating to scratch your suspected diamond.

This test is that many mineral crystals look like diamonds and offer considerable hardness. And among the list is Corundum, which refers to the ruby and sapphire groups. Corundum ranks nine on the Moh’s scale, meaning if it scratches your suspected gem, it’s not a raw diamond. But if your stone happens to scratch Corundum, then there’s a strong chance you have the real thing. Still, it helps to run every other test to be sure.

Specific Gravity

Diamonds possess a gravity of 3.5 to 3.53g/ml (the ratio of a stone’s density to a pure liquid of thickness 1g/ml. So, when testing for the specific gravity of your suspected raw diamond, this is the number you’re looking for. To test the stone’s specific gravity, follow the procedures below;

  1. Weigh the suspected gem on an accurate electric scale. Ensure you’re using one that only goes below a maximum of two to three decimal places after the whole number. Once done, record the result for later use, as this is the gem’s original weight.
  2. Fill a paper with water such that the stone can submerge in it. Take care not to overfill it, so it doesn’t spill. Then, put the cap on the scale’s center and set the result to zero.
  3. Roll the stone with a paper clip so it forms a hanger you can hold to submerge it. Then, carefully dip the stone into the water till it submerges, without touching the cup’s sides of the bottom.
  4. Take the result displayed on the scale as the gem’s weight in water. Then calculate as original weight divided by weight when submerged in water.

If you get a result of around 3.5 to 3.53g/cm3, you may have a raw diamond in hand. But anything less is probably moissanite or quartz.

Location and Frequency

Diamonds developed in ultrabasic igneous rocks called kimberlite pipes, meaning if you find a gem close to one of these sites, it may be a diamond. Such pipes occur in ancient cratons, which are also the most geologically stable portions of the earth’s surface. And these rocks are less likely to contain feldspar or quartz but will hold at least 35% olivine. Diamonds from kimberlite pipes are either found when the igneous rocks are broken (blue rock) or after they’ve been weathered by river action (yellow rock). And the latter is mostly deposited on banks of flowing water, which can be traced back to highlands of kimberlite origins.

But while diamonds can be found in such regions, they don’t always occur in large deposits, and the chance of finding more than two stones at a go is slim. In some cases, tectonic motion releases enough heat and pressure to form micro-diamonds. However, such is rare and limited to the extremely volcanic areas of Canada, Japan, China, Europe, Indonesia, and Russia.

Other Properties To Identify

While these are the most regularly used tests for knowing a raw diamond, you can still consider other tells, like the ones below;

  • Raw diamonds exhibit smooth, flat cleavage surfaces. But if you witness conchoidal fractures instead, you have a quartz crystal. But unless the stone is already fractured when found, don’t try to break it yourself.
  • Diamonds are very resistant to heat, so try heating the gem for a long time. If it breaks, then it’s not a raw diamond.
  • If you’re fishing for raw diamonds in a given location, gather the slurry and pour it on a greased table. The raw diamonds will stick to the greasy surfaces, while the others will flow off with the water.
  • Try observing the crystal under U.V. light, as 30% of diamonds display a light blue fluorescence in such conditions. Of course, some may also express a glow of white, yellow, red, or orange.

Buying A Raw Diamond

If you’re buying a raw diamond, you’re going with an expert who understands how to fish for these things. But if you don’t have one, then using these features is the key to ensuring you’re getting the real thing. Rough diamonds can be used in their original forms as jewelry, and many have come to appreciate this fashion style. And if you’re lucky, you may get good quality and grade for as little as $150!

But it helps to note certain factors before buying, and below, we’ll list the most important ones;

  • Always ask for the raw diamond’s grading certification. You can tell the clarity and color with its report and decide how many carats you’re taking. The sweet thing about buying a raw diamond for jewelry is that you won’t have to cut it.
  • Request for its Kimberly certificate to ensure that the stone is ethically sourced. This option achieves two purposes; you’ll be sure the stone isn’t conflict-related, and you can tell if it’s a natural or lab-made stone.
  • If it’s a lab-made stone, ask for a quality appraisal from the manufacturer. Also, note that lab-grown raw diamonds are cheaper than natural ones, so they’ll offer good value for money.


Coming across a raw diamond is fortunate, especially since they’re mostly quite valuable in their original state. But not all presented or found gems with similar crystalline appearance pass as the real deal, which is why having foreknowledge about the gem is paramount. Here, we’ve offered you an in-depth look at a raw diamond, including its physical and gemological properties. And, we hope you’ll put this information to good use when seeking such stones for whatever reason so that you can gain optimum value from its trade with little wasted effort.