Gemstones for Beginners: How to Choose the Right Gemstones for Your Jewellery

The world of gemstones can seem baffling for those who have never studied it in depth. Most of us are content to simply admire the beautiful stones and vibrant colours from the outside.

Moreover, buying a piece of fine jewellery is usually an emotional experience. We are buying it as a gift for someone or for ourselves to mark a special occasion. And when there's such a wide array of stones, colours, cuts, shapes and styles, an already emotional experience can quickly turn overwhelming.

You want the stone you choose to reflect your personality and style, but it's also good to learn a bit more about the qualities that make these gemstones valuable.

The science of gemstones is called gemology. Each gemstone has a unique and compelling story to tell, starting with its formation, through its journey from the mine to the shop where you bought it and ending with its new home in your collection.

So, before you go out and buy your very own piece of gemstone jewellery, learn more about what you should be looking for with our short, beginner-friendly guide to the fascinating world of gemstones.

What Is a Gemstone?

Gemstones are most commonly minerals in the form of crystals which are used to adorn jewellery after being cut and polished. These include popular examples like diamonds, sapphires, emeralds and rubies.

However, some organics are also categorized as gemstones. They may not be minerals, but they are also cut, polished and used to create jewellery. Examples include pearls, ammolite, jet and amber.

When mineral and organic gemstones are used to make jewellery, they are chosen based on their beauty, rarity and durability. This is why not all minerals can be considered gemstones because not all will have the same aesthetic and monetary value.

However, the popularity of specific gemstones fluctuates with changing tastes and trends. What remains constant is the desire for beautiful, eye-catching jewellery.

Gemstone Treatments

There is an ever-growing spectrum of treatments for coloured gemstones with the goal of increasing their value.

Heat treatment is widely used to intensify colour in sapphires and rubies. It's paired with diffusion treatments that fuse colour into the surface of the gemstone. When it comes to gemstones, such as topaz, tourmaline, and fancy diamonds, irradiation is occasionally employed to enhance their colour. These treatments are usually permanent.

Cavities on the surface of the gemstone that would normally detract from its value can be filled with glass-like substances, while glass and plastic resins can be used to repair fissures, fractures and laser drill holes.

Emeralds are commonly described as 'oiled' because coloured coatings are applied to increase the intensity of their natural colour. A gemstone that has undergone such treatment will need to be handled with more care because extreme heat, ultrasonic cleaning and detergent can damage the coating.

A reputable gemstone laboratory will look for signs of these treatments and include their findings in the gemstone's report. Keep in mind that some of these treatments are considered controversial because they can increase the beauty of gemstones that would otherwise be unsuitable for use in jewellery designs. Untreated natural gemstones are very rare in certain categories, which means they command a much high price.

Gemstone Classification

Coloured gemstones were previously separated into two categories: precious and semi-precious. Due to the scarcity and high cost of some "semi-precious" stones, this distinction has been dropped, and now they're referred to simply as gemstones.

Still, it goes without saying that some gemstones are much more expensive than others, and if you're buying jewellery with an expensive gemstone like an emerald, sapphire or ruby, it would be wise to insist on getting an identification report from a gemological laboratory. As we mentioned before, the report will also include any treatments that the gemstone was subjected to.

Reputable retailers already have gemstone reports from internationally recognized laboratories like The Certified Gemological Laboratory of Europe (CGL) and The Gemological Institute of America (GIA).

The Four Cs of GemstonesColour

The beauty of most coloured gemstones comes from their colour, and there's a wide variety to choose from. Note that the more vivid and clear the gemstone is, the higher the price.

The colour of a gemstone is determined by three factors:

• Hue: Hue describes the dominant colour of a gemstone, as well as other visible colours.

• Tone: Tone describes the lightness or darkness of a gemstone.

• Intensity or saturation: Intensity or saturation refers to the hue's purity.

Most customers simply pick the colour they find the most beautiful. There are always small variances in terms of these three factors, so you can ask the jeweller to show you several options and explain the differences between them.

Carat Weight

Gemstones are measures in carat weights. One carat means a fifth of a gram, and each carat is subdivided into 100 points to allow for very precise measurements.

As a rule of thumb, the larger the gemstone, the rarer it is, which will be reflected in the price.

The jewellery industry also measures gemstones in millimetres since this needs to be considered when matching them to rings, earrings, pendants and other types of jewellery. Note that two gemstones can have the same size but different weights because of the mineral mass or pressure.

Clarity

Clarity refers to the degree to which a gemstone's appearance and structural integrity are unaffected by inclusions, fractures, or surface flaws. Inclusions are materials trapped inside the gemstone.

The beauty of coloured gemstones is generally enhanced by their clarity because the way light passes through a gemstone affects its aesthetic appeal unless it is opaque and blocks all light.

Certain gemstones, such as the majority of tanzanite pieces, have few inclusions that obstruct the flow of light. Others have distinctive inclusions. Emeralds, for instance, have characteristic inclusions that are dense and look mossy or like a garden which is why these inclusion patterns are referred to as "jardin" – the French word for garden.

Cut

The cut of a gem, often known as its shape, is just as important as the rest of the stone's features. It describes its shape and how it's crafted. Smooth rounded surfaces are better suited for some gemstones like opal, while others, like sapphire, are typically cut with a precise succession of flat, symmetrical planes known as facets to produce that appealing illumination of the gem's colour.

These days, some cutters also use convex or concave facets to shape coloured gemstones into miniature sculptures.

When choosing between an oval, round, pear, marquise, triangular, or emerald-shaped stone, consider how its facets are placed, its proportion and finish. All three of these factors add to the stone's beauty and monetary value.

Gem cutters are always striving for that perfect balance of safe shape, weight and mix of colour.

Cynthia Madison is a young blogger and economics and marketing graduate. She writes about home, lifestyle and family topics and is a senior contributor to popular niche publications.