Gemstones are natural creations, each carrying its own unique traits and imperfections. While buying or evaluating gemstones, terms like cracks and inclusions often come up, which can impact both the value and durability of the stone. However, many people find it difficult to differentiate between the two. Understanding the difference between cracks and inclusions in gemstones is essential, especially when choosing stones for jewellery or astrological purposes. This blog will help you understand what cracks and inclusions are, how they differ, and why inclusions are not always a bad thing.
What are the Cracks in Gemstones?
Cracks in gemstones are physical breaks or fractures that usually extend from the surface into the interior of the stone. These cracks can occur naturally during the stone’s formation or later due to improper cutting, handling, or impact. They often weaken the structure of the gemstone and can affect its durability over time.
Cracks are usually visible to the naked eye or under magnification and may appear as white lines or jagged breaks. In some cases, cracks can also cause a loss of shine and transparency. Gemstones with cracks are generally considered less valuable, especially if the cracks are deep or reach the surface, as they can lead to further damage or breakage. Using proper techniques during cutting and setting can help reduce the chances of cracks forming or worsening. However, once a gemstone has developed a crack, its structural integrity is compromised to some extent.
What are the Inclusions in Gemstones?
Inclusions in gemstones are internal characteristics formed during the natural growth of the stone. These can be solid crystals, gas bubbles, liquids, or mineral traces trapped inside the gemstone. Unlike cracks, inclusions are a part of the gemstone’s internal structure and are not caused by external damage.
Inclusions can vary in shape, size, and type. Some may appear as small dots, threads, clouds, or even patterns that are unique to a specific gemstone variety. For example, the silky inclusions in Kashmir sapphires or the needle-like rutile in rutilated quartz are well-known features that can even add to a gemstone’s appeal. While inclusions may lower the clarity grade of a gemstone, they don’t always reduce its value. In fact, in many natural gemstones, minor inclusions are expected and can serve as proof of authenticity. They help gemologists identify the origin and formation process of the stone.
Cracks vs Inclusions in Gemstones: Key Difference
Understanding the key differences between cracks and inclusions in gemstones helps you make better choices when buying, valuing, or wearing gemstones especially for jewellery and astrological use. Here’s a detailed explanation:
Formation Origin
Cracks are the result of external forces. They usually form due to physical stress, accidental impact, sudden temperature changes, or improper cutting. In some cases, cracks may develop after the stone is already set in jewellery due to daily wear and tear.
Inclusions develop naturally while the gemstone is forming underground. They are a part of the crystal growth process and often carry geological information about the stone’s origin. These may be solid minerals, tiny crystals, gas bubbles, or fluid-filled pockets.
Appearance
Cracks usually look like sharp, uneven lines or fractures that disrupt the gemstone’s natural structure. These lines may appear white, silvery, or dark depending on how light reflects off the broken edges.
Inclusions can vary greatly in appearance. They may look like clouds, needles, feathers, veils, or dots. Some inclusions are visible without magnification, while others are microscopic. Certain types, like “silk” in sapphires or “jardin” in emeralds, are commonly accepted and even admired.
Location in the Gemstone
Cracks usually start at or reach the surface of the gemstone. They may extend inward and sometimes create a visible weakness across the stone.
Inclusions remain entirely enclosed within the gemstone. They do not extend to the surface and usually sit deep inside the crystal.
Impact on Durability
Cracks are structural weaknesses. Over time, a gemstone with noticeable cracks is more likely to chip, split, or break, especially if it is worn regularly in rings or bracelets.
Inclusions, unless unusually large or heavily clustered, generally do not compromise the stone’s durability. Most natural stones have minor inclusions that do not impact performance or wearability.
Effect on Value
Cracks often lead to a significant reduction in the gemstone’s market value. Even if the color and cut are good, visible cracks are viewed as damage and can make a stone less desirable.
Inclusions may reduce the value depending on their type, size, and location. However, in many high-value gemstones like ruby, emeralds, and sapphires, small inclusions are accepted. In fact, a perfectly flawless stone is often viewed with suspicion unless verified as synthetic or treated.
Identification
Cracks can be seen with the naked eye or under slight magnification. In some cases, they are visible as white or dark lines when the stone is tilted under light.
Inclusions may require professional tools like a jeweller’s loupe or microscope to identify clearly. Trained gemologists study these internal features to determine the gemstone’s type, origin, and treatment status.
How to Identify Cracks and Inclusions in Gemstones Accurately
Identifying whether a gemstone has a crack or an inclusion is an important step before buying or valuing it. While both may appear similar at first glance, especially to the untrained eye, there are clear differences that can be spotted with the right techniques and tools.
Visual Inspection with Magnification
The first step in identifying cracks or inclusions in gemstones is to use a 10x jeweller’s loupe or a microscope. Under magnification, cracks appear as sharp, irregular lines that disrupt the surface or travel deep into the gemstone. Inclusions, by contrast, appear as internal features such as tiny dots, clouds, thread-like lines, or mineral shapes. While both may affect clarity, the edges of cracks are usually more jagged and reflective under light.
Surface Feel Test
One simple method to tell the difference is by gently running your fingernail over the suspected line. If the line is a crack, your nail may catch slightly, indicating it reaches or breaks the surface. Inclusions, being internal, will not affect the outer smoothness of the gemstone. This method is especially helpful when examining set stones where full magnification is not possible.
Light Reflection Behavior
When you move a gemstone under strong white light, cracks often reflect light sharply, causing bright flashes or interruptions in the stone’s sparkle. These disruptions occur because the crack interferes with light flow. In contrast, inclusions in gemstones may appear soft or shadow-like and do not usually reflect light in the same intense manner. The difference in light behavior can help distinguish between structural damage and natural internal patterns.
Shape and Pattern Recognition
Cracks usually form in unpredictable, jagged, or branching patterns, much like lightning bolts. Their irregular shape is a clear sign of breakage. On the other hand, inclusions tend to follow more natural, recognizable forms such as needles, clouds, or crystals. Certain inclusions may even resemble moss or feathers, especially in stones like emeralds or sapphires. Recognizing these common patterns can assist in accurate identification.
Expert Assessment
For gemstones with unclear features or those of high value, it is best to consult a certified gemologist. They can provide a professional evaluation using advanced tools and lab techniques. An expert can confirm whether the visible feature is a crack or an inclusion, assess its impact on the stone’s durability, and explain how it affects overall quality and value.
Why are Gemstone Inclusions Important?
Inclusions in gemstones are natural internal features that provide valuable clues about the stone’s authenticity, formation, and origin. For example, emeralds often contain visible inclusions known as “jardin” (meaning garden), which confirm their natural growth. Similarly, sapphires may have silk-like inclusions that help experts identify if the stone is untreated. These internal marks act like fingerprints, helping gemologists differentiate natural stones from synthetic or treated ones. Inclusions unique to certain regions like the “three-phase” inclusions in Colombian emeralds can also help trace a gemstone’s source, which may influence its value.
Some gemstones are even appreciated more because of their inclusions. Rutilated quartz, for example, contains golden or silver needle-like structures that give it a distinct and desirable appearance. In moss agate, the inclusions look like green moss or plant-like patterns, making each stone one of a kind. Inclusions are also used to confirm gemstone type and identify treatments like heating or fracture-filling. Unlike surface-reaching cracks, inclusions in gemstones typically do not weaken the stone unless they are unusually large. They play a positive role in confirming a gem’s natural origin and adding unique character.
FAQ
1. Are inclusions bad in gemstones?
Not always. Inclusions are common in natural gemstones like emeralds, sapphires, and rubies. They can help verify authenticity and, in some cases like rutilated quartz or moss agate, even add visual appeal.
2. Can cracks in gemstones be repaired?
Some surface cracks can be filled using fracture-filling techniques, but the process may affect the gemstone’s value. It’s important to ask for full disclosure of buying a treated stone.
3. Do inclusions reduce the value of a gemstone?
Minor inclusions may not affect value much, especially in valuable gemstones like emeralds or rubies. However, heavy or visible inclusions in transparent stones can reduce clarity and overall worth.
4. How can I tell if a gemstone has a crack or an inclusion?
Use a jeweler’s loupe or microscope. Cracks usually reflect light sharply and may be felt on the surface. Inclusions are enclosed inside the stone and may appear as needles, dots, clouds, or crystals.
5. Do all natural gemstones have inclusions?
Yes, most natural gemstones have inclusions. Flawless stones are rare and often indicate synthetic or treated gems..
Conclusion
Understanding the difference between cracks and inclusions in gemstones plays a vital role in selecting, valuing, and maintaining your gemstones, whether for jewelry, collection, or astrological purposes. Cracks are surface-reaching breaks caused by external damage, which can weaken the stone’s structure and reduce its durability and value. On the other hand, inclusions are naturally occurring internal features that form during the crystal’s growth. While they may affect clarity to some extent, they often serve as important indicators of a gemstone’s natural origin and authenticity.
Being able to identify inclusions vs cracks accurately helps you make informed decisions when buying precious stones like emeralds, rubies, sapphires, and quartz. Minor inclusions are common and acceptable in most natural gemstones, while visible cracks usually signal a lower-quality or damaged stone. Whether you’re choosing a gemstone for investment, personal wear, or spiritual reasons, always inspect the stone carefully or seek guidance from a certified gemologist to ensure you’re getting a piece that is both beautiful and durable.
