Cracks Vs Inclusions
Publised on Aug 29, 2018
One of the most troubling dilemma that customers face when buying gemstones is how to discriminate between an inclusion and a crack. While the visual difference between the two is not apparent to everyone, scope of either’s presence can have an impact on gemstone’s use in the longer run. In addition, the way an inclusion appears can differ from one gemstone to another. However, some insight into the basic nature of cracks and inclusions can help customers to understand not only the worth of gemstone but can also equip them with better understanding of gemstone’s overall quality.
WHAT ARE INCLUSIONS?
Inclusions are natural impurities found in the gemstones and develop while the stone is being processed in nature’s womb. Some of these impurities are quite essential and add character to gemstones, increasing their worth for humans. E.g. presence of an insect trapped in Amber, can highly increase its worth. Likewise, thin golden needle like crystals of rutile can enhance the value of Quartz. In addition, presence of inclusions implies that the gemstone is real and not an artificial replica synthesized in laboratories. Yet, not only the nature but volume, location and density of inclusions can weaken the gemstone’s strength and scope of use in long run. For this reason, one thumb rule in gemstone trade goes as ‘lesser the inclusions, better is the quality of gemstone’. Obviously, the exceptions exist.
HOW TO TELL IF IT IS A CRACK OR INCLUSION?
Visually, especially to a naked eye, both crack and inclusion can appear same. But knowing where and how far to look can help you differentiate between the two.
1. SURFACE REACH
One basic rule that goes for cracks is that they begin from inside of gemstone and end up on the surface. Whereas inclusions usually lay inside the gemstone and do not change spots.
Inclusions are inherent to gemstones,i.e. they are formed right when the gemstones are being processed in the nature. Crack on the other hand, can be an inclusion gone wary, appearing much later. So, if you did not see the imperfection before, chances are it is a crack that has appeared later in the gemstone.
While both inclusions and cracks can appear anywhere on the gemstone, a crack usually finds its passage where the inherent structure or gemological composition of the stone is weaker. Usually, outer edges around metal (in case of jewelled gemstones) are the spots where cracks appear.
No outside force or pressure can cause inclusions whereas outside pressure, gradual wear & tear or rough handling of gemstones (like heavily faceted cutting or negligence) can cause cracks. Meaning, cracks can emerge outside or inside of the gemstone. Some organic or naturally brittle gemstones are more likely to crack sooner than other gemstones like Red Coral, Pearl and Emeralds.
Inclusions are characteristic in nature and may differ in appearance, structure and composition whereas a crack lacks these traits. E.g. in Yellow Sapphire or other sapphires, inclusions would appear as white line (Silk) whereas a crack may reflect rainbow like spectrum, not because of any specific character but because of exposure to light.
These are some of the most identifiable differences between cracks and inclusions. However, since each gemstone is unique and has a complex gemological composition, it takes a trained eye and sophisticated equipment to clearly identify the either one.