What is Ruby Clarity

As with any natural gemstones, rubies have clarity inclusions that form within the gemstone as it is forming in the earth. A ruby is the amalgamation of various minerals and substances and so, each piece is unique. Clarity refers to the presence of inclusions, that can affect the transparency and impact how it emits and reflects light. The vast majority of natural rubies contain inclusions. Rubies that do not have inclusions are highly valued and immensely rare. Inclusions impact the light performance and color of the ruby. Learn more about ruby color.

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Types of Inclusions in Natural Rubies

Various types of inclusions can form within a ruby. Each has a different structure and a different appearance. Different types of inclusions can affect the value of the ruby in different ways. Inclusions can typically be seen with the naked eye, while others can be seen with a 10x microscope.

silk like needle inclusions in a ruby


These inclusions look like silk fibers that are commonly found in clusters. They are on the insides of the ruby and look like fine fibers. These inclusions can have litle impact on ruby color and clarity. In mass quantity, they can whiten the ruby and discolor the beautiful red glow and hue. They can affect light performance as well.

natural crystals growing in the ruby


The are more solid inclusions that are of various shapes and sizes. They can look like small pinpoints or grains. Because, crystals are typically white or black, their signficantly impact the rubies color, visibility and light performance. All rubies have inclusions, but avoid those with crystal inclusions.

larger thin needle inclusions in a ruby


These are long and slender inclusions that are either crystals or narrow tubes. They often look a bit glassy and impact light performance, but less so on color. When larger, they can look like a scratch inside the ruby. Ideally, they are located away from the surface so lower visibility in the gemstone.

natural cracks like feathers growing in the ruby and breaking the surface

Crack or Feather

are also known as fractures and fissures that can be featherlike in appearance. These inclusions will break the surface of the gemstone and can impact the structural integraty of the ruby. Because rubies are soft, these can be dangerous inclusions when the size is large

twinning wisps growing in the ruby where a crystal grows through another crystal


These are also crystals but are structurally two that are growing out of one another. Twinning makes crystals more visible because the size of the overall crystal gets larger. They can impact the visibility of the inclusion and diminish light performance and whiten (or darken) color, depending on the color of the crystal.

small fingerprint like inclusions clustering in the ruby


These are quite common in rubies. The inclusions are clustered together and look like small human fingerprints. Because the inclusions are small, they are less likely to impact the quality of the ruby. Only if they fill the ruby up, then you can have issues with the light perfomance and red hue.

a cavity found on the ruby


These are miniscule holes that extend into the ruby from the surface of the gem. Large cavities are visually unattractive and make a ruby look broken. Additionally the can affect the structural integrity of the ruby, especially when setting the ruby in jewelry.

natural crsytals growing in the ruby

Scratches, Abrasions

These are surface blemishes that look like rough scrapings on the surface of the ruby. Scratches can often be polished away; however, it depends on the size, location and depth of the scratch. If very deep, a lot of weight loss may result from a scratch. Additionally, scratches are typically quite visible because they are surface inclusions.

Color Zoning in the ruby affects it's evenness of red

Color Zoning

All rubies are primarily red but do have other secondary colors. Uneven colors is when the color does not look uniform across the surface of the ruby. Inclusions can often cause color zoning making portions of the ruby look pink. Color zoning is also something impacted by the cutting of the ruby. Cutters try to preserve the red hue and tone to make the color even.

Clarity Grading

Rubies are typically graded on a letter scale with AAA being the best and ranging down. Four Mine uses only AAA graded rubies. These are the top 10% of natural rubies that are available. They have minimal eye-visible inclusions and a beautiful transparency. Because of this, they are also structurally sound and durable, making them easy to work with. It also ensures that light can reflect through the ruby and both the color and the sparkle of the gem can shine through. AAA rubies have the perfect blend of color, clarity and cut and are the perfect quality for use in any kind of jewelry. Avoid lower grade rubies as they can be opaque, included and lifeless.a

Clarity Enhancing Treatments

Often times, treatments are used to enhance or improve the clarity of the ruby. While some are common, and permanent, others are not as desirable. It is important to understand the differences between all types of treatments.

Heated Rubies: The most commonly used treatment is heat. The majority of rubies are heat treated to remove rutile inclusions and improve the color tone and saturation. This treatment is permanent and mimics the natural processes that rubies undergo while forming. It is a common treatment that enhances the value and the appearance of natural rubies. While undergoing this treatment, the ruby is placed under a high temperature of 1800 degrees. The heat dissolves the rutile inclusions and improve the color, transparency and clarity of the ruby. The resulting ruby is as natural, durable as the original ruby before treatment. No other additives or materials are used to alter the ruby is any fashion. Four Mine uses only heat treated natural rubies to ensure the highest quality and durability in all jewelry that we create.

Flux Healed Rubies: Often times, rubies are coated in a material prior to heating. This creates a barrier and prevents the rubies from sticking together during the heating process. At times, this flux materials can mlt and enter the cracks and fissures that are in a ruby. This can improve the clarity of the ruby by filling in the cracks. However, the treatment introduces foreign substances into the ruby and therefore decreases it’s value. Four Mine does not use any flux healed rubies to craft jewelry.

Beryllium Diffused Rubies: In this treatment, beryllium is added to the ruby as it is being heated. This treatment enhances the color of the ruby producing a more vibrant red color. The beryllium permeates the crystal lattice of the gemstone. Four Mine does not use any rubies that are treated with beryllium diffusion.

Glass Filled Rubies: This is a newer treatment that is used to enhance lower grade rubies. The ruby is bleached and treated with the addition of a liquified glass. The glass penetrates the ruby and improves the clarity of the ruby. The visibility of the cracks is lessened. However, this treatment is the least desirable as it is not stable with temperature changes or when the ruby is subjected to ultrasonic cleaners. Four Mine does not use any rubies that have been glass filled or treated.

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