Much of the time, people walk into the store with some idea of the type of gemstone they’re looking for. Maybe they’re after the perfect diamond engagement ring, for example, or a stunning sapphire necklace.

Often, we forget just how unique the range of precious gemstones can be, and the sheer variety they come in. Add in the incredible rainbow of brilliant colours to choose from, and there are countless ways to find an authentic one-of-a-kind stone to pair with your custom jewellery.

Diamonds, rubies, sapphires and emeralds are four of the most valuable and sought-after gemstones in the world. For anyone looking to purchase an outstanding engagement ring with an impressive gemstone here are some interesting facts and features of these four sparkling beauties.

A beautiful gemstone is a symbol of your love. Knowing the meanings and uses behind each gemstone can help you decide what you want to say with your custom piece of jewellery.

What Are “Precious Stones”?

“Precious stones” is a name that is usually used in reference to four types of gems: diamonds, rubies, sapphires, and emeralds. Precious stones are usually transparent and cut by faceting – like the stones shown in the accompanying image.

In regards to the so-called « precious stones », only four prevail diamonds, rubies, emeralds and sapphires. Sometimes you will see that a pearl, an opal or jade are listed as a precious gemstone, but more often they are considered semi-precious. Traditionally, these four precious stones have been the most expensive and sought after stones.

Some people have included opal, jade, or pearls in the “precious stones” class, but these have not received persistent and widespread use.

Separating stones into “precious” and “semi-precious” classes has led many people to believe that “precious stones” are more important and more valuable than “semi-precious stones.”

This idea is somewhat supported by the fact that diamonds, rubies, sapphires, and emeralds generally cost more per carat than semi-precious stones. Precious stones also account for over 98% of the dollar value of gemstone imports for consumption.

Diamond – The Forever Gem

Diamond is renowned for its superlative physical qualities, most of which originate from the strong covalent bonding between its atoms. In particular, it has the highest hardness and thermal conductivity of any bulk material. Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths of 150 to 250 kilometres (93 to 155 mi) in the Earth’s mantle, although a few have come from as deep as 800 kilometres (500 mi). Marketing has significantly affected the image of the diamond as a valuable commodity.

However, many people expect a diamond to be unbreakable. This is not true. A diamond’s crystal structure has ‘hard’ and ‘soft’ directions. A blow of sufficient force, in an exact direction, can crack, chip, split or even shatter a diamond. The Crater of Diamonds State Park in Arkansas is the world’s only diamond mine open to the public, and this is a dig-for-fee operation for tourists and rock enthusiasts. An average of 74,000 visitors comes to the park each year. About one out of 100 visitors find a diamond.

Diamonds symbolise forever love, which is why they’re most commonly given as engagement and wedding rings. Diamonds that surpass the ‘z-light yellow’ rating on the diamond colour scale are considered fancy yellow diamonds. Fancy yellow diamonds are extremely rare and typically cost more than colourless diamonds. Because of their rarity, they’ve become a symbol of Originality.

The hardest naturally occurring material on earth that can only be cut or scratched with another diamond. Its name comes from the ancient Greek adámas meaning “unbreakable”. No gemstone on the planet contains as much allure and interest as does Diamond.

Possessing the highest shine of all transparent gemstones, the way diamonds reflect light is without equal. Its rarity, beauty and strength make it a fitting symbol of resilience and longevity of marriage.

A diamond has four characteristics: clarity, cut, colour and carat known as the “4 Cs”. Each characteristic has an impact on the cost and price of a diamond.

Diamond is the birthstone for April and 60th Wedding Anniversary.

Sapphire – The Prosperity Gem

After diamonds, sapphires are the next hardest gemstone. Pure sapphires are actually white, but in the presence of titanium and iron traces, they acquire a velvety blue colour. Sapphire in any other colour but blue are called “Fancies”.

Sapphire is also a variety of the mineral Corundum and represents all the colours except red corundum, which is Ruby. Its physical and chemical properties are virtually similar to the properties of Ruby. Blue is the main colour of the sapphire, whereas this gemstone is also found in colours like green, orange, pink, grey, colourless, black, brown, and purple. The word ‘Sapphire’ in its plain context refers only to blue sapphire unless a prefix colour is specified. Sapphire with a colour other than blue is often called a ‘Fancy’ in the gem trade. The Sapphire gemstone symbolises harmony, friendship and loyalty.

Sapphire is the most precious blue gemstone. It is the most desirable gem due to its colour, hardness, durability, and lustre. Value of this gemstone depends on its size, colour and transparency. Top-quality sapphires are extremely rare in all the gemstone mines of the world. Cutting off this gemstone requires great skills and experience, and it is the job of the cutter to orientate the raw crystals in such a way that the colour is brought out to its best improvement.

Sapphires come in a variety of colours and cuts. It’s no surprise this gem is known as the stone of prosperity. The most famous sapphire is the 12-carat oval blue Ceylon sapphire of the royal family engagement ring. It’s currently worn by Kate Middleton and was originally worn by Lady Diana Spencer. Its restorative properties are known to help alleviate mental tension and promote inner peace.

The world’s most famous sapphire engagement ring is a 12-Carat Blue Sapphire previously owned by the late Diana, Princess of Wales, and currently worn by Catherine, Duchess of Cambridge.

Sapphire is the birthstone for September and 55th Wedding Anniversary.

Emerald – The Original Royal

Known for its green shade and a clear depth of colour that very few gems possess, emerald is the precious stone that symbolises renewal and hope.

Emerald is one of the most fascinating and beautiful gemstones. Emerald is a precious gemstone and a variety of the mineral beryl coloured green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. The crystals are usually small with an average length of 2 – 5 cm and width of 1 – 1.5 cm. Larger crystals are usually semi transparent to opaque. 

The most desirable colour is slightly bluish-green in a medium-dark tone with strong to vivid saturation. Clarity is important, but inclusions are tolerated more in this variety than virtually any other gem. Top-quality, unenhanced stones (with certification) can bring as much as 50% more in price than treated stones of the same size, colour, and clarity.

Emerald is known for its soothing properties. Wearing an emerald ring is a sign of mature humility in a relationship. It’s a bold choice as an engagement ring and a reaffirmation of a strong love. The emerald was once believed to help couples with infertility. This precious stone symbolises renewal and hope.

Its captivating green colour is unique and unparalleled in all other gemstones. Along with diamonds, blue sapphires and red rubies, the green emerald is one of the “big four” most valuable gemstones in the world. The most desirable emerald colours are bluish-green to pure green, with vivid colour saturation and tone that’s not too dark. The most-prized emeralds are highly transparent.

Emerald is the birthstone for May and 20th Wedding Anniversary.

Ruby – The Romantic Gem

Rare, unique and valuable, the ruby is the most sought-after gemstones after diamonds.

A variety of the corundum family, ruby is famous for its deep red hue and vibrant glow. Bearing the colour of love and desire, ruby is the ideal romantic gift for a woman in love.

Ruby is the red variety of the mineral corundum, one of the hardest minerals on Earth, of which the sapphire is also a variety. Corundum is the mineral form of alumina which crystallises in the hexagonal system—the red colour of ruby results from a small admixture of chromic oxide. Only red corundum is entitled to be called ruby, all other colours being classified as sapphires. The most prized tint is blood red or crimson known in the trade as ‘pigeon’s blood’ red.

The quality of a ruby is determined by its colour, cut, and clarity, which, along with carat weight, affect its value. The brightest and most valuable shade of red called blood-red or pigeon blood commands a large premium over other rubies of similar quality.

Those who wear ruby gems often choose to do so as an expression of their birthstone. It’s also known to bring good luck and protection. Ruby is most desired in its pure red colour with a hint of blue. The ruby gemstone is known to inspire passion and devotion, which is why it’s often given as a symbol of deep love and romance.

If you’re shopping for loose sapphires and gemstones, our non-commissioned gemstone experts are ready to guide you to the perfect choice! Get started by scheduling a visit to the Padis Jewelry showroom.

Like sapphires, red rubies are second only to diamonds in their hardness and brilliance. Transparent rubies of large sizes are even rarer than diamonds and sapphires.

Ruby is the birthstone for July and 40th Wedding Anniversary.

What Are “Semi precious Stones”?

Every other gemstone that isn’t one of those four is considered to be semi-precious. The list goes on and on, but some of the more common ones are: alexandrite, agate, amethyst, aquamarine, garnet, lapis lazuli, moonstone, opal, pearl, peridot, rose quartz, spinel, tanzanite, tourmaline, turquoise and zircon.

This separation between precious and semi-precious has no real scientific backing. For example, emerald is a variety of beryl, so are aquamarines. Emerald is precious while aquamarine is semi-precious. When this categorisation came about, it was mainly due to the value and rarity differences between the four precious gemstones and the rest. Today some semi-precious gemstones can be worth much more than a precious stone. As an example, many natural pearls garner huge prices, often worth more than a low-quality precious diamond, ruby, emerald or sapphire. Spinels are another example. Additionally, many semi-precious stones can be rarer than some of the precious. Demantoid garnets or tsavorite garnets and many other semi-precious gemstones are hard to find, harder to mine and produced in much lower qualities than the precious gemstones.

When purchasing a gemstone, we wouldn’t suggest getting too caught up if the stone is precious versus semi-precious. All gemstones are precious, in the sense that if they provide meaning and value to you in a piece of jewellery, they are special! Bare in mind that colours are subjective and a piece of jewellery is emotional.

The names “semi-precious stones” and “semi-precious stones” are used for all varieties of gemstones that are not categorised as “precious.” Any gemstone suitable for being used in personal adornment would be included.

Some people believe that the word “semi-precious” is derogatory, irreverent, misleading, or confusing and that its use should be discontinued. They think that there should be “precious stones” and “other stones”. Perhaps these people want to cast all gems but a “precious few” under a derogatory light?

Unfortunately, eliminating the word “semi-precious” from use would be extremely difficult. Over the past 150 years, scores of popular books have been written with the word “semi-precious” in their titles.

Today the terms repeatedly appear in thousands of books, magazines, web pages, and other documents published by companies in the gem and jewellery industry, government agencies, and the most influential institutions in gemology. Purging these terms from professional use would be difficult, but, eliminating them from common use would be nearly impossible – especially because some people really like these names.

Common Misconceptions About Precious Gems

The division of gemstones into the categories of “precious” and “semi-precious” might give some people the idea that “precious stones” are more valuable, rarer, more beautiful, or more desirable than “semi-precious stones.” Here are just three of the problems with calling some stones “precious” on the basis of their value, rarity, beauty or desirability.

There are a number of common misconceptions about precious gems or gemstones, especially the Big Four.


One of the most common misconceptions about Diamonds, Rubies, Sapphires, and Emeralds is that they are the rarest gemstones in the world.

All gemstones are rare to some degree whether it be Tanzanite from Africa or Rubies from Sri Lanka.

The special circumstances required to create a gemstone, pressures, heat, combinations of unique minerals, all come together to form a gem or gemstone.

However, when we look at how rare one gemstone is compared to another, there are many gemstones that are much rarer than the gemstones that are known as the “Big Four”; Rubies, Emeralds, Diamonds, and Sapphires.

For example, Red Beryl is much rarer than any of the so-called precious gemstones commanding a hefty price of nearly $10,000.00 per carat.


Many believe that the “Big Four” are the most valuable and expensive gemstones in the world. There are many examples of gemstones that are much more valuable than any of the “Big Four” gemstones.

High-quality Jadeite can exceed the price per carat of the most costly diamonds with a hefty price of nearly $3,000,000.00 per carat.

Precious stones are distinguished by their quality, their rarity and the beauty of their colours. There are only four precious stones: diamond, sapphire, ruby and emerald. All other stones are therefore called semi-precious stones.

This distinction is also due to their hardness, which translates into scratch resistance. One stone is harder than another if the former can scratch the latter. Only a diamond can scratch another diamond. However, it can still crack in the event of a major shock.

On the other hand, the term “semi-precious stones” does not mean that they are less beautiful than precious stones. The best known of these are amethyst, topaz, peridot, citrine, aquamarine or green tourmaline. The range of semi-precious stones offers an infinite palette of colours and shades that is much wider than all the colours of the precious stones put together. It is always better to use a beautiful aquamarine rather than a poor-quality sapphire.

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