Inclusions 101: What You Need to Know About Diamond Inclusions

Diamonds are often used to mark the beginning of an epic love story. But long before a round brilliant cut stone was set into a ring and placed on your finger, it had endured long and intense journey of its own—one that often leaves unique marks.

Most people know that diamonds form deep within the Earth under immense pressure and heat. This intense geological process can sometimes leave behind tiny imperfections known as inclusions—almost like birthmarks for humans. While inclusions are considered to be flaws and can impact the value and appearance of a given stone, they actually tell a fascinating story about a diamond’s long journey before it reached your finger.  

How Do Inclusions Form?

Inclusions are essentially mineral crystals, trace elements, or other foreign materials that are trapped within the diamond as it grows. They can be extremely small and nearly impossible to see, or large enough to few without magnification. The type and number of inclusions in a diamond depend on various factors, including the specific geological conditions under which the diamond formed.

Inclusions are distinct from blemishes, which are another type of “imperfection” that can impact a diamond’s clarity grade. Inclusions refer to a diamond’s internal composition, while a blemish refers to an external irregularity or flaw on the surface of the stone.

A large platinum ring with a round brilliant cut diamond containing visible inclusions

Common Types of Inclusions

  • Crystals: A mineral crystal contained in a diamond. These are the most common type of inclusion and can be extremely small or large enough to see without magnification.

  • Pinpoint A very small crystal that looks like a tiny dot at 10X.

  • Needle A thin, elongated crystal that looks like a tiny rod at 10X.

  • Clouds: Many tightly grouped pinpoints or crystals that might be too small to distinguish individually, but together create the appearance of a cloud or haze.

  • Cavity: An opening in the diamond’s surface, usually created when an internal inclusion is breached during the polishing process.

  • Feathers: A fracture or crack within the diamond, often appearing as thin, feathery lines.

  • Graining:  The result of irregular crystal growth, appearing as lines or waves that appear whitish, colored, or reflective, or affect transparency at 10X.

  • Twinning wisp: A series of different inclusions (pinpoints, clouds, feathers) that form a chaotic pattern while a diamond is growing

The Impact of Inclusions on Diamond Value

Inclusions are a natural part of the diamond formation process, but depending on the type, size and location, they can significantly impact the clarity grade of a diamond and its value. Most diamonds have inclusions to some extent; however, not all inclusions are created equal. Some inclusions, such as those that are small, colorless, and well-positioned within the diamond, may have little to no impact on its value. Large inclusions that are eye-visible or affect the structural integrity of the stone can result in a lower grade and a lower value.

Generally, diamonds with fewer and less noticeable inclusions are considered more valuable. The GIA Clarity Scale considers the size, nature, position, color or relief, and quantity of inclusions and blemishes to assign a clarity grade to a stone. Truly “flawless” diamonds are exceedingly rare, so VVS (Very Very Slightly Included) is often the highest clarity grade you’ll see.

A gold ring featuring several oval salt-and-pepper diamonds
14k Gold Salt & Pepper Diamond Eternity Band

Salt and Pepper Diamonds

A fascinating subset of diamonds with inclusions are known as “salt and pepper” diamonds, which are characterized by a distinctive speckled appearance caused by many visible inclusions.

While traditional diamond grading standards might consider these inclusions as flaws, many people find the rustic charm of salt and pepper diamonds to be incredibly appealing. They offer a more affordable alternative to flawless diamonds while still possessing a stunning natural beauty.

Beauty in Imperfection

A diamond’s inclusions should not necessarily be considered undesirable; indeed, they are a natural and fascinating aspect of the diamond world. They offer a glimpse into the stone’s unique journey and formation process, as well as add unique character and charm that reflects your own one-of-a-kind personality or relationship.

When it comes to picking a diamond that speaks to you, there’s no “right” or “wrong” answer. Whether you prefer a flawless diamond or one with a touch of natural imperfection, the right jeweler will help you understand the impact of inclusions and find the right stone for your lifestyle.