How to Describe and Quantify Gemstones


Via: Unsplash.

Gemstones are some of the most remarkable nuggets generated from the Earth's natural geological processes. However, most are more common than you think, and the price they sell is based on more than just the type of gem offered. So we are here to set the records straight and tell you how to describe and quantify gemstones so that you can understand why one diamond might sell for a lot more than another.  

How to Describe and Quantify Gemstones?


Via: The Valkyrie.

The Basics of Gemstones

Describing a gemstone requires that you first understand the processes of its making.

For example, if you have ruby, you’d need to know they form in metamorphic rocks, lasting over 30 million years to develop fully. So for a ruby that is not lab-made, there is a finite amount of them and thus making them rare.

On the other hand, diamonds are formed in igneous rocks, where specific pressures and temperatures combine, affecting and transforming the chemical element carbon over millions of years. 

So with these examples in mind, you can start to understand what makes gems chemically different from each other and thus have different elemental and physical properties. This is fundamental to understanding why we describe and grade gemstones differently. 

The Four C’s of Gemstone Grading

The four ‘c’s are what gemologists evaluate, define, and value each gemstone specimen that comes into their care. It also sets them up for sale for gemstone consumers by providing them with the basic properties, pricing and grade of the gemstone. 

  1. Color


Via: Unsplash.

You determine the gem's colour by focusing on three elements: hue, tone and saturation. Generally, the highest-valued gemstones often have pure hues, rich colors, and the highest saturation intensity. 

  • Hue:  This is the actual color that people often think about when they describe a gem in a fundamental sense, such as a red ruby or a pink diamond. These primary hues are: red, purple, yellow, orange, green, blue and violent. It should be noted that black, white and brown are not hues but tone and saturation. 

  • Tone: The tone of a gem refers to the gemstone’s reflective lightness or darkness. A scale defines these through white to black tones. 

  • Saturation: A gem's saturation refers to the hue's intensity, so how strong or soft the color presents. This could describe how cold or warm something is or how saturated or desaturated. 

    1. Cut 


    Via: Ganoksin Jewelry Making Community.

    The cut of a gem is all about the stone’s shape, proportions and size,  finishing off the piece with a polish before it's ready to show off all its best qualities. It also makes it visibly appealing to potential buyers or those looking to turn them into jewellery. Diamonds benefit from this cut perhaps the most out of all precious gemstones, as its color is not as crucial as its glowing saturation. 

    Above, you can see some popular gemstone cuts currently on the market. But there are three types of basic cuts that we will briefly discuss now.

  • The Brilliant Cut
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    Via: International Gem Society

    The Brilliant cut of the gemstone has triangular and kite-shaped facets that come from the center of the stone. It is an absolute favorite with gem lovers as it gives excellent scintillation (sparkles) based on how the facets reflect light. 

  • The Step Cut
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    Via: International Gem Society

    A step cut is adored because it shows off a piece that might have brilliant, fantastic color. It would be silly to cut a plain gem like a diamond this way, and you’d prefer to get a ruby or emerald cut like this. The steps allow for subtle scintillation but without removing the hues. 

    1. The Mixed Cuts

    Via: International Gem Society

    Mix cuts over various options for gems that want enough glow and surface to show off their brilliant natural hues. 

    1. Clarity



      The clarity of a gem is determined by the internal landscape of the inclusions or blemishes on the exterior of the stone. Inclusions could include tiny minerals, crystals of other gems, microscopic gas bubbles, small liquid pockets, fractures or cleavages, or any other visible matter. 

      Fractures are common gems, but they might cause instability for the gem, so people may often choose not to go ahead with a purchase if they are concerned about these aspects of the stone.  Gemstone cleavages are the measurement by which gems might crack in half due to fractures or other structural integrity issues. 

      Essentially, the clarity of a gem isn’t about its color or appearance as such but the little details in its form that might show imperfections in its formation. It is important to note these as they can cause the stone to break if unchecked. They also highlight the gemstone's purity if other types of minerals make up its structure.

      1. Carat


      Via: Unsplash.

      The term ‘carat’ is often thrown around in gemstone and jewellery circles with little understanding of this measurement. Essentially, a carat is a measuring weight of gems that, in metric terms, equates to one-fifth of a gram. So the more a gemstone weighs, the more it will be valued and adored!

      However, every gemstone is formed differently, so as a result, its density will be different. This means that the value of each type of gem will need to be measured only against gems of the same kind. A diamond that is twice as heavy as a ruby might still be worthless in this regard. The same is said if they weigh the same, but if two rubies were weighed and one had a higher carat, then that heavier one would be worth more. 

      Gem Stone Rings


      Via: Unsplash.

      Cubic Zirconia from Thorum


      Via: The Athena.

      Thorum has a range of gemstones in its wedding rings collection, but the most iconic is of course the cubic zirconia rings. These have the beauty, sparkly and elegance of real diamonds, whilst also being very affordable for the ‘common person’. Although CZ is not a naturally occurring gemstone, and made in a lab, it is still popular amongst gemstone lovers.

      Check out our complete collection of Cubic Zirconia  rings.

      Other Precious Gemstones from Thorum


      Via: The Magni, from Thorum made of artificial fire opal. 

      Opal is one of the most incredible stones it comes in a variety of hues, and its is also very bright and sparkly. It is made through a combination of silica and water developing as hard rock formations over millions of years, and is a commonly mined rock in Australia. 

      However, in the stones used for rings made by Thorum (shown above) we used artificially made one sin a lab to ensure the right hues and pieces everytime! The benefits of lab-made is its cheaper with a better try and quality over randomness and rarity. 


      Via: The Prospector, from Thorum made of turquoise stone. 

      This natural gemstone part of the Thorum rings collection is turquoise sourced from Arizona. Its brilliantly aqua blue is formed through veins in volcanic rocks in various processes, or sedentary rocks which are phosphate rich. 

      Final Remarks: How to Describe and Quantify Gemstones


      Via: The Aphrodite.

      The art of describing and quantifying gemstones is a very complex affair. We’ve only touched the tip of the stone in terms of introducing the ins-and-outs of gems and how geologists go about telling one stone from another. At least with this knowledge you’ll be able to understand and shop for gemstones more efficiently!

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