A "needle" type inclusion within a diamond refers to a long, thin, needle-like crystal. As a clarity characteristic, needle inclusions are generally of no consequence (no concern).
We consider needles one of the more favorable inclusion types because they're usually minute and difficult to locate. Most needle-like inclusions appear long, thin, and translucent or slightly white under 10x magnification.
The Gemological Institute of America (GIA) names most inclusions depending on their appearance. In that case, the name "needle" is aptly appropriate given the inclusion's long, thin, needle-like appearance.
This photograph shows two needle inclusions within a round brilliant-cut diamond at 35x magnification. The green arrows indicate the location of the needle inclusions, which appear to be very slight (VS) and of no consequence.
What is a "needle" within a diamond?
Most needle-shaped inclusions within diamonds are smaller crystals absorbed during the larger crystal's growth process. However, needle-shaped inclusions may also contain other minerals and crystal growth remnants.
The appearance of the needle inclusion depends on its size, quantity, and orientation within the diamond. Those characteristics are taken into account when determining the diamond clarity grade.
For example, a needle inclusion within a VS2 clarity diamond will be more prominent than one within a VS1 clarity diamond. However, more than one inclusion and additional considerations may contribute to the overall clarity grade, such as internal graining, surface graining, external blemishes, etcetera.
Is a diamond needle inclusion bad?
Generally speaking, a needle-like inclusion is a needle-shaped diamond crystal without concern or consequence. It's just a smaller diamond trapped within the larger diamond crystal as it formed.
Whether a needle-shaped inclusion is concerning or of no consequence depends on its impact on the diamonds' overall appearance and clarity grade. In our experience, most needles are translucent or white and difficult to locate, which makes them a desirable inclusion type.
However, every diamond must be considered individually on its own merits. If the inclusions are minute and scattered, they're not likely to have any impact on the diamond's beauty or structural integrity. Under those circumstances, minute inclusions like needles do not present significant concern.
Clusters of Needle-shaped Inclusions
If the needle-shaped inclusions are significant, numerous, or tightly clustered, they could impact the diamonds' visual appeal. However, under those circumstances, the diamond grading report will reflect an appropriate lower clarity grade.
Consequently, a high concentration of needle inclusions is not necessarily an issue. This extreme close-up from GCAL highlights a cluster of needle-shaped diamond crystals in an HPHT lab-grown diamond. The formation resembles a constellation of glittering stars and is of no consequence.
Diamond Clarity Considerations:
Although needle-type inclusions rarely present concerns to diamond buyers, here is a list of things to consider:
1. Clarity: Determine whether the needle inclusions are prominent or affect the diamond's transparency. Are the inclusions readily and immediately visible to the naked eye, or does seeing them require magnification?
2. Durability: Needle inclusions under the table facet aren't likely to affect the diamond's structural integrity. However, the significant presence of any inclusion type may affect structural integrity, especially if along the diamonds' edge.
3. Reflections and Light Performance: Needle inclusions are unlikely to interfere with light entering and reflecting within the diamond. However, it's always good to examine inclusions using magnification to determine the extent of their appearance.
Diamond Clarity Guidelines:
When buying a diamond, it's essential to consider the nature of the overall clarity grade and appearance. That means the cumulative effect of all inclusions within the diamond, including size, quantity, location, and visibility.
Naturally, higher-clarity diamonds are less likely to contain significant inclusions than those with lower clarity. However, the mind-clean benefits of higher clarity come with additional costs due to higher diamond prices.
It's all about knowing how to balance a diamond's characteristics to maximize the benefits while minimizing costs is essential. Thankfully, most needle inclusions are minimal in appearance and don't pose an issue. In that case, they're a safe bet and nothing to worry about.
For example, this photograph from GCAL shows multiple needle inclusions within a natural diamond under extreme magnification. The needle-shaped inclusions are barely visible and clearly of no consequence.
Considerations for Today's Diamond Buyer:
As a buyer, it's essential to inspect the diamond using a jeweler's loupe or a microscope to assess the visibility and impact of inclusions. The following online vendors provide high-resolution videos that make it easier to verify inclusions:
Please use our free Diamond Concierge Service for assistance evaluating the characteristics of any diamonds you're considering. Consider consulting an independent gemologist who can help you make an informed decision.
In summary, most needle-shaped inclusions are no reason for concern. They are one of our favorite types of inclusions because they're mostly diamonds within diamonds. Assuming that the needles are minimal in size and appearance, they're not likely to be of any consequence.