Guide to Diamond Inclusions

Diamonds have captivated humankind for centuries. Beyond their dazzling brilliance, these precious gemstones often bear markings known as inclusions. These natural features provide invaluable insights into a diamond's growth process and create distinct personalities within each stone. In our guide to diamond inclusions, embark on a journey into the world of diamond inclusions, exploring their types and the stories they tell.

Types of Diamond Inclusions

Diamond inclusions develop from the incredible heat and pressure applied to diamonds during their creation. Nearly each one possesses internal and external clarity characteristics known as inclusions. These characteristics help gemologists determine natural diamonds from synthetics and simulants, as well as provide quality gradings for individual gems.

Common Diamond Inclusions


Feathers are one of the most common types of diamond inclusions. These internal fractures resemble delicate plumes and can vary in size, shape, and orientation. Formed during the diamond's tumultuous formation deep within the Earth, feathers offer a glimpse into the immense pressure and heat endured by these extraordinary gemstones. While smaller feathers may be insignificant, larger ones may impact a diamond's durability and even affect its optical performance.


Crystals, also known as mineral inclusions, are a dazzling display of nature's artistry within diamonds. They can appear in various shapes, colors, and arrangements, giving each diamond a unique personality. Common types of crystals include garnets, pyrites, and olivines. These mesmerizing inclusions often provide a striking contrast against the diamond's colorless or colored body, creating captivating patterns and mesmerizing landscapes.


Pinpoint inclusions are tiny, almost microscopic, crystals within a diamond. These minuscule specks can be either white or black, and their presence depends on the diamond's formation process. Pinpoints may form due to trapped fluids or minerals, and their size and density vary. While they are generally not visible to the naked eye, clusters of pinpoints can create a cloud-like effect, potentially impacting a diamond's transparency and overall beauty.


Cloud inclusions consist of numerous pinpoint inclusions that appear in clusters, creating a hazy or cloudy appearance within a diamond. These formations often result from the presence of tiny gas bubbles or other mineral impurities during the diamond's growth. While clouds can be challenging to detect without magnification, densely populated clusters may impact a diamond's brilliance and transparency.


Needle inclusions are extremely thin, elongated inclusions that resemble tiny needles within a diamond. These inclusions can be colorless or possess a range of hues. Needles are often composed of other minerals or diamond crystals themselves. Depending on their density and distribution, needle inclusions may impact a diamond's clarity and transparency.

Twinning Wisp 

Twinning wisp inclusions are complex formations that occur when multiple crystal growth directions intersect within a diamond. They often appear as wispy, ribbon-like patterns, showcasing the intricate dance of crystal formation. Twinning wisps can include various inclusions, such as pinpoints, crystals, or feathers, creating a captivating display within the diamond.

Indented Natural 

Indented natural inclusions occur when the rough diamond's natural surface is not entirely removed during the cutting and polishing process. These inclusions may appear as depressions or rough patches on the diamond's surface. While indented naturals are considered part of a diamond's natural character, their siz


round cut diamond

Round cut diamond with crystal, feather, needle and cloud inclusions

Click to view the entire GIA certificate for this diamond

Rare Diamond Inclusions  


Bruise inclusions manifest as areas of damaged diamond material resulting from external forces or trauma. These inclusions can appear as dark patches or areas of alteration within the diamond. Bruise inclusions may affect the clarity and structural integrity of a diamond, and their presence should be considered when evaluating a stone.


Chip inclusions are characterized by small fragments or missing parts of a diamond's surface. They occur when a diamond sustains a sharp impact or encounters rough handling. While minor chips may be repairable, larger chips can significantly impact the appearance and value of a diamond. Proper diamond maintenance and regular inspections can help prevent and address chip inclusions.


Cavity inclusions are hollow spaces or voids within a diamond. They can result from the dissolution of mineral inclusions during the diamond's formation or from the removal of inclusions during the cutting process. Cavity inclusions may affect a diamond's structural integrity and overall clarity. The presence and size of cavities should be carefully considered when evaluating a diamond's quality.


Knot inclusions are clusters of diamond material that extend from the diamond's interior to its surface. These inclusions occur when a diamond crystal intersects the surface during growth and is subsequently covered by additional diamond material. Knot inclusions can present challenges during the cutting and polishing process and may affect a diamond's overall clarity and durability.


Graining inclusions are irregularities or distortions within a diamond's crystal lattice structure. These inclusions result from the diamond's growth process and can appear as faint lines, streaks, or textures within the stone. While some graining inclusions may be difficult to detect, others may impact a diamond's transparency and brilliance.

Diamond inclusions are like nature's fingerprint on diamonds, providing a window into the diamond's formation process and the immense forces it endured. While some inclusions add a touch of intrigue and individuality, others may affect a diamond's beauty and structural integrity. When choosing a diamond, it is important to consider the type and impact of inclusions, balancing their presence against other desired qualities such as color, clarity, and cut.

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