Importance Of Gemstones Inclusions

Man has been interested in Gems and Jewelry from time immemorial and has been under its enchanting charm since ages, mainly due to their aesthetics and rarity value and their associated symbolism. The word, gemstones, brings into mind wonderful and perfect cut stones with that appealing twinkle in the light. 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 over all authenticity and in some cases, value.

In this blog we will discuss what gemstone inclusions are, what types of gemstone inclusions exist, how such inclusions stages work in relation to the gemstone properties and why inclusions is such an important topic for any gemologist and jeweller. Thus, by the end of the project, you will grasp the fact that those tiny features inside the gems possess a great importance 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 that are present in the interior of a gemstone and they include 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 hence are genuine formations. When the gemstone is forming the mineral, fluids, or gases may be enclosed and they get trapped within the gemstone.

Contrary to what most people believe that inclusions are defects, they may not always be so. In fact, they can even add value and distinctiveness to the gemstone, based on the kind of inclusion and the way it looks like. 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 in the assessment of the grade, value and even the 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 is interspersed in the gemstone in form of small crystals. For example, in the sapphire some impurities of mineral called rutile is found which occur in thin needle like structures and impart an optical phenomenon known as ‘silk’.

Liquid Inclusions: At times, there can be small ‘vugs’ of liquid which become surrounded with a certain gemstone. These types of inclusions are mainly constituted of water, brine or CO 2. 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, a methane or some other gas.

Healing Fractures (Feather Inclusions): The formation processes of gemstones involve pressure and other forces besides heat, and that is why some of the 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 looks like thin cracks and even while impairing clarity, they may not be regarded as imperfections.

Needle Inclusions: Needle-like inclusions referred to as elongated filled structures resembling needle like or hair like structures. They are also known to occur in different gemstones including sapphires, garnets and emeralds. These inclusions can be arranged in a manner to give the singular optical effect refer 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 out of 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 is able to deduce the geological nature of the gemstone formation, including the formation temperature, 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, presence of inclusions that are within sapphires may be used to determine the place that the stone came from, since it is a key aspect when it comes to the valuation of the stone.

Gemstone inclusions also give information into how long it took to develop a gemstone. Too fast rate of cooling of magma or other mineral bearing fluids will cause the formation of gems with many inclusions while slow rate of cooling will give birth to clearer gems.

4. Inclusions and Gemstone Authenticity

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

For instance, natural emerald may have “jardin” which is French for garden as they depict moss like trap within the stone. These inclusions are believed to be perfectly natural within the formation of natural emeralds and are used for differentiation of the synthetic material.

Also, different bodies in a diamond are used to distinguish natural diamonds from synthetic or simulated diamonds, for example, small black carbon spots or tiny crystals. They include; pattern, type, and the distribution of the inclusion can actually assist the gemologists to confirm 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. Plus, some inclusions may increase the gem’s worth, depending on a number of aspects.

Impact on Clarity: In the majority of 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 therefore 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 which produced a star are sought after due to their unique optical features. Likewise, such amber stones that have fossils in them or plant material tend to be treasured as rare and important antiques.

Inclusions as Evidence for Provenance: Some inclusions say in case of Burmese rubies or Colombia Emeralds may serve as more than decoration but increase the value of the gem as well. 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 for the purpose of improving their observations and even their colors. However, such processes also change or remove some features making those inclusions not to be seen. When such inclusions are closely looked at by gemologists, they are able to 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 gemstones that are fractured. A material including glass or resin is injected to the fractures in order to disguise them. Inclusions seen round the borders of the filled area would help gemologists to conclude whether fracture filling has been done or not.

7. Inclusions as a Gemstones’ Adornment

In relation to the foregoing, one of the inclusions 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 any 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 there are no inclusions in gemstones is hardly an option, as it serves an artistic 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 character of the stone. 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 to understand and assess gemstones as they give information about the stone’s origin, treatment and its quality. Inclusions can show if it is natural, if it is synthetic, if it has undergone treatment, and what the provenance is.