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What Do Diamonds Look Like in the Ground? Unveiling Nature’s Hidden Gems

Diamonds, those sparkling symbols of love and luxury, begin their journey in a far less glamorous state. In their natural habitat deep within the Earth, they are far from the perfectly cut and polished gems we see in jewelry stores. To the untrained eye, a raw diamond can easily be mistaken for a common pebble or shard of glass. They typically resemble lumps of pale, colored glass, often possessing a greasy or oily luster. Unlike their brilliant, faceted counterparts, rough diamonds have a dull, rough exterior. Their color can vary from colorless to yellow, brown, green, and even less common shades like pink or blue. The crystal structure, typically an octahedron or dodecahedron, is a key identifying feature, although this can be obscured by weathering and surface irregularities. Finding diamonds requires knowing what to look for, understanding the geological context, and employing techniques to distinguish these hidden treasures from ordinary rocks.

Identifying Diamonds in the Rough

Discovering diamonds in their natural state requires a keen eye and a good understanding of their key characteristics. Here’s a breakdown of what to look for:

Appearance: Forget the sparkle! Look for irregularly shaped stones with a greasy or waxy luster. The surface will be rough, not smooth like polished glass. The color is often pale, with yellowish, brownish, or grayish hues being the most common.
Crystal Structure: Although often partially obscured, try to identify the octahedral or dodecahedral shape. These shapes are indicative of the diamond’s inherent crystal structure.
Hardness: Diamonds are renowned for their extreme hardness. A scratch test can be performed (with caution!). If the stone can scratch corundum (the mineral that makes up rubies and sapphires), it’s a strong indicator that you might have a diamond.
Density: Diamonds are denser than many other common rocks. If you have access to measuring tools, you can perform a density test. A diamond has a density of 3.5 – 3.53 g/cm3. This means that a diamond will sink in water quicker than most other rocks.
Location: Understanding the geological setting is crucial. Diamonds are primarily found in kimberlite and lamproite pipes, which are volcanic formations that brought the diamonds from deep within the Earth. They can also be found in placer deposits, where they have been transported by water and accumulated in riverbeds or coastal areas.

Where to Look for Diamonds

Knowing where diamonds are likely to be found greatly increases your chances of success. Here are some key locations to consider:

Kimberlite and Lamproite Pipes: These are the primary source rocks for diamonds. They are often weathered and eroded, but their presence indicates a potential source. Kimberlite, also called blue ground, is a dark-colored, heavy igneous rock that contains diamonds in its rock matrix.
Placer Deposits: These are secondary deposits where diamonds have been transported and concentrated by natural processes. Look for them in riverbeds, gravel deposits, and coastal areas.
Historical Mining Sites: Areas where diamonds have been mined in the past may still contain undiscovered gems. Tailings, the waste gravel from old mining operations, can sometimes yield diamonds. The Crater of Diamonds State Park in Arkansas is one such location, open to the public for diamond hunting. At the Crater of Diamonds, diamonds come in all colors of the rainbow, are white, brown, or yellow.

Identifying Features and Tests

While visual identification is important, several tests can help confirm whether a rock might be a diamond:

The Scratch Test: This is a classic test to verify the hardness of a diamond. Only a diamond can scratch another diamond, or corundum (the mineral that makes up rubies and sapphires).
The Water Test: Due to their high density, diamonds will sink in water. This can help differentiate them from less dense stones. Because loose diamonds are so dense, they should sink to the bottom when dropped in a glass of water.
The Light Test: Diamonds have a unique way of reflecting light. Observe how the stone interacts with light. A real diamond will reflect light easily, and provide you with a disco ball or rainbow-like display. The inside of a real diamond should sparkle gray and white while the outside should reflect a rainbow of colors onto other surfaces.
Professional Appraisal: The most reliable method is to have the stone examined by a qualified gemologist. They have the tools and expertise to accurately identify and assess diamonds.

Differentiating Diamonds from Other Stones

Many stones can resemble diamonds in their rough state. It’s crucial to differentiate between them:

Quartz: Often mistaken for diamonds due to their glassy appearance, quartz is much softer and less dense.
Moissanite: A synthetic gemstone that closely resembles diamonds. However, moissanite has a different refractive index and can often be identified using specialized tools. Moissanite is the only gemstone that passes as a diamond on a handheld point test.
Cubic Zirconia: Another synthetic diamond simulant, cubic zirconia is less hard than a diamond and has a different thermal conductivity.

Responsible Diamond Hunting

If you are planning to search for diamonds, it’s crucial to do so responsibly:

Obtain Permission: Always obtain permission from landowners before searching on private property.
Respect the Environment: Avoid damaging the environment during your search. Fill in any holes you dig and leave the area as you found it.
Follow Regulations: Be aware of any local regulations regarding diamond hunting, especially in public areas like the Crater of Diamonds State Park.

Frequently Asked Questions (FAQs)

Here are some frequently asked questions about finding diamonds in the ground:

What color are most raw diamonds?

Most raw diamonds exhibit shades of yellow, brown, or gray. Colorless diamonds are rarer in their natural state. At the Crater of Diamonds, diamonds are white, brown, or yellow.

What is the host rock for diamonds called?

The primary host rock for diamonds is kimberlite, also known as blue ground. It is a dark-colored, heavy, often altered, and brecciated igneous rock.

How deep do I need to dig to find diamonds?

The depth varies depending on the location. In some areas, diamonds can be found on the surface after rain washes away the soil. Most visitors like to dig in the soil and screen for diamonds, usually searching through the first six inches to one foot of soil. At places like Crater of Diamonds State Park, rain washes the soil away, leaving diamonds and other rocks and minerals exposed on the surface.

Can I find diamonds in my backyard?

It’s unlikely, unless your property is located in a known diamond-bearing area.

What are tailings?

Tailings are the waste gravel from old mining operations. These piles can sometimes contain diamonds that were missed during the original processing.

How can I tell if a rock is a diamond without special equipment?

Perform a scratch test on corundum or use the water test to check its density.

What shape are most raw diamonds?

Most raw diamonds form in octahedral or dodecahedral shapes.

What should I do if I find a diamond?

If you find something that looks like a diamond, take it to a qualified gemologist for identification and appraisal.

Are all diamonds sparkly when they are found?

No, raw diamonds are not sparkly. They have a dull, greasy luster.

Is it legal to keep diamonds I find?

The legality depends on the location. In some areas, you are allowed to keep what you find, while others require you to report it. If you find diamonds in your backyard, always attempt to find the owner if possible, or turn the item in to the police. Most states will allow finders to keep the property if the owner does not show up to claim it after a certain time. Failure to report a found item can lead to criminal charges.

What kind of soil are diamonds found in?

Diamonds are found in soils derived from kimberlite and lamproite, as well as in placer deposits.

What’s the easiest way to identify a diamond?

By holding a diamond close to a source of light, such as a flashlight, you can tell whether or not it’s real. Watch closely for the shimmers of light that shine from the stone.

Can a mirror scratch a diamond?

No, only a diamond can scratch a mirror.

What are some rocks that are commonly mistaken for diamonds?

Quartz, moissanite, and cubic zirconia are often mistaken for diamonds.

What are diamond mining tools that I could use to find diamonds?

Diamond mining tools are available for rent or purchase at the park. Plowing is unscheduled but generally takes place once a month during spring, summer, and fall. Historical structures and mining equipment, washing pavilions, and sun shelters are located in the search area.

Finding a diamond in its rough form is a thrilling experience. By understanding what to look for and where to search, you can increase your chances of discovering these hidden treasures. Remember to always be respectful of the environment and follow local regulations.

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What do diamonds look like in the ground?