Importance Of Gemstones Inclusions

Man has been interested in gems and jewelry from time immemorial and has been under their enchanting charm for ages, mainly due to their aesthetics, rarity value, and associated symbolism. The word gemstones brings wonderful and perfectly cut stones with an appealing twinkle in the light into mind. However, one important aspect of gemstones that is easily overlooked is the presence of inclusions. These internal features are not flaws as most people would think, but they give much-needed data about the geologic background of the gem and its overall authenticity and, in some cases, value.

In this blog, we will discuss what gemstone inclusions are, what types exist, how such inclusion stages work with the properties, and why inclusions are such an important topic for any gemologist and jeweler. Thus, by the end of the project, you will grasp that those tiny features inside the gems are important in gemology.

1. What are Inclusions? 
2. Types of Inclusions

a) Crystalline Inclusions

1. 1. 1. Crystalline Inclusions
      2. Liquid Inclusions
      3. Gas Inclusions
      4. Healing Fractures
      5. Needle Inclusions
      6. Fingerprint Inclusions

1. What Are Inclusions in Gemstones?

Inclusions are internal characteristics present in the interior of a gemstone, including crystals, fractures, liquid bubbles, and other materials that are foreign to the gemstone. These inclusions are developed as the gemstone grows within the earth’s crust and are genuine formations. When the gemstone is forming, the minerals, fluids, or gases may be enclosed, and they get trapped within the gemstone.

Contrary to what most people believe, inclusions are defects, but they may not always be so. They can even add value and distinctiveness to the gemstone based on the kind of inclusion and how it looks. Impurities will also reveal many details about the gemstone matrix and the conditions within which the gemstone was formed.

2. Types of Gemstone Inclusions

Knowledge of the various categories of the inclusions helps assess the grade, value, and likelihood of its being a fake gemstone. Here are some of the common types of inclusions found in gemstones: Here are some of the common types of inclusions found in gemstones:

Crystalline Inclusions: These are other minerals formed during the birth of the gemstone, which are interspersed in the gemstone in the form of small crystals. For example, in the sapphire, some impurities of mineral called rutile are found, which occur in thin needle-like structures and impart an optical phenomenon known as ‘silk’.

Liquid Inclusions: At times, small ‘vugs’ of liquid can be surrounded by a certain gemstone. These inclusions are mainly constituted of water, brine, or CO2. At times the liquid is still fluid within the stone and thus gives it an extra graceful touch to its look.

Gas Inclusions: Inclusions within the gemstone are relatively rare, though they are common in particular types of gems, such as quartz, in which the trapped gas bubbles form. These inclusions can occur as small roundish ovoids and may contain carbon dioxide, methane, or other gases.

Healing Fractures (Feather Inclusions): The formation processes of gemstones involve pressure and other forces besides heat, which is why some gems develop cracks. These cracks may heal partially over time and leave a trace in the form of ‘feathers.’ Feathers refer to patterns on the gemstone that look like thin cracks, and even while impairing clarity, they may not be regarded as imperfections.

Needle Inclusions: Needle-like inclusions are elongated-filled structures resembling needle-like or hair-like structures. They also occur in different gemstones, including sapphires, garnets, and emeralds. These inclusions can be arranged to give the singular optical effect referred to as asterism, as witnessed in the star sapphires.

Fingerprint Inclusions: Such inclusion looks like the whorls and loops left by a fingerprint. They are created from heald partial fractures in which the crack contains liquid or gas. These are called ‘fingerprints’ due to their unique, spiral-like patterns.

3. The Part Played by Inclusions in the Formation of Gems

They also give much-needed pointers on the conditions within which a gemstone would be formed. By looking at inclusions, a gemologist can deduce the geological nature of the gemstone formation, including the formation temperature and the formation pressure, among others.

For instance, the inclusions of fluids in crystals such as diamonds hold information on the Earth’s mantle because diamonds are formed under high pressure and with a high temperature beneath the surface of the Earth. In the same manner, the inclusions within sapphires may be used to determine where the stone came from since they are a key aspect of the valuation of the stone.

Gemstone inclusions also explain how long it took to develop a gemstone. A rate that is too fast to cool magma or other mineral-bearing fluids will cause the formation of gems with many inclusions, while a slow rate of cooling will give birth to clearer gems.

4. Inclusions and Gemstone Authenticity

Most of the time, inclusions are the approximations that define whether a gemstone is natural or synthetic or has been treated in any way. Most natural gemstones formed over millions of years normally have inclusions, while most synthetic gems prepared in laboratories may have few or different inclusions.

For instance, natural emeralds may have “Jardin,” French for the garden, as they depict moss-like traps within the stone. These inclusions are believed to be perfectly natural within the formation of natural emeralds and are used to differentiate the synthetic material.

Also, different bodies in a diamond are used to distinguish natural diamonds from synthetic or simulated diamonds, such as small black carbon spots or tiny crystals. They include pattern, type, and the distribution of the inclusion, which can actually assist the gemologists in confirming the identity of the gemstone.

5. Inclusions and the Value of Mineral Stones

The value of any gemstone with inclusions may depend on the situation, as the inclusions may or may not lower its value. Some inclusions may increase the gem’s worth, depending on several aspects.

Impact on Clarity: In most cases, inclusions tend to impair the clarity of gemstones and, therefore, may negatively affect their market price. For example, a diamond exhibiting a low level of inclusions is preferred for its clarity and is, thus, more expensive in value. The clarity scale developed by the Gemological Institute of America (GIA) classifies gemstones into a spectrum with ‘flawless’ also known in abbreviation as FL, and, ‘included’ abbreviated as I where gemstones in the former category are the most expensive.

Intriguing Inclusions: In contrast, excluding the interest or being bothersome, some inclusions have a positive effect on the gem, adding more beauty and or rarity to the stone. For instance, in this case, star sapphires whose compositions are made up of rutile inclusion grew in a way that produced a star are sought after due to their unique optical features. Likewise, such amber stones with fossils or plant material tend to be treasured as rare and important antiques.

Inclusions as Evidence for Provenance: Some inclusions, such as in the case of Burmese rubies or Colombia Emeralds, may serve as more than decoration; they may increase the value of the gem. Valuable gems tend to come from these prestigious mining regions, and at the same time, their inclusions do indicate where they came from.

6. Inclusions and Gemstone Treatments

Inclusions also assist in revealing if the stone was treated or not. Most received treatments to improve their clarity or color or even both, and where there are inclusions, some procedures suggest why they are there.

Heat Treatment Heat treatment is mostly performed on sapphires and rubies to improve their observations and even their colors. However, such processes also change or remove some features making those inclusions not seen. When gemologists closely look at such inclusions, they can determine whether heat treatment has been carried out or not.

Fracture Filling Fracture filling is when fillers are used to enhance the visual qualities of fractured gemstones. A material including glass or resin is injected to the fractures to disguise them. Inclusions seen around the borders of the filled area would help gemologists to conclude whether fracture filling has been done or not.

7. Inclusions as a Gemstone’ Adornment

About the preceding, one of the inclusions of appreciation in a gemstone is its artistic value apart from scientific and monetary value. The common practice in the industry is that clean stones free of inclusions are the preferred options, yet certain inclusion types would add to the beauty of a gemstone.

Inclusions Creating Optical Phenomena: Some inclusions result in the formation of interesting and very marketable appearances of the gems. A case in point is asterism, a rutile inclusion mostly floral in shape that produces a star-like pattern. This is also termed the cat’s eye and is another optical effect produced by some inclusions in stones like chrysoberyl, where a stripe of illumination moves around the stone.

Artistic Inclusions: For gemstone cutters and jewelers, ensuring no inclusions in gemstones is hardly an option, as it serves a creative purpose instead. Most facets of every single gemstone depict the most significant geological histories.

Inclusions in Circles: In cabochon-cut stones (cut in the spheres semi-spheres), inclusions are often acknowledged as enhancing the stone’s character. In this case, instead of being a flaw, inclusions in stones cut into a cabochon may act to beautify the stone, particularly in the case of the opal. 

For gemologists and jewelers, inclusions are important aids in understanding and assessing gemstones as they give information about the stone’s origin, treatment, and quality. Inclusions can show if it is natural if it is synthetic if it has undergone treatment, and what the provenance is.