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The Best and Worst Engagement Ring Gemstones

Gemstone engagement rings are becoming increasingly popular due to their unique style, large size, and lower cost. However, these aren’t the only factors that go into purchasing an engagement ring – you have to consider the durability of the gem, too.

All gemstones have different hardness levels, and not all are suitable centre stones, even if you’re looking for the most unique engagement rings on the market. It’s important to understand which gemstones will stand up to your daily life, and which may break easily during normal wear. The Mohs Hardness Scale can detail which stones are suitable, and which are not.

What is a gemstone engagement ring?

A gemstone engagement ring is a type of engagement ring that has a non-diamond centre stone. Often designed using traditional engagement ring settings, such as solitaires, halos and three-stones, some couples choose less traditional settings to hold their unconventional centre stone.

Common choices include sapphires, emeralds, and rubies. Aquamarines, amethysts, morganite and tanzanite are gaining in popularity too – however, some of these stones won’t stand up to daily wear.

Benefits and risks of gemstone engagement rings


Benefits to gemstone engagement rings include personality, uniqueness, and cost. Some couples like to express themselves in colour; a bright red ruby can symbolise passion, or a rich sapphire loyalty.

Gemstones are livelier than some diamonds and they won’t cost quite as much either. Depending on the stone, size and colour, gemstones are often a fraction of the cost of a similarly sized diamond.

So, couples choosing a gemstone engagement ring can often afford a larger centre stone in a different gemstone than they could in diamond. Many gemstones grow in large crystals, which also means that many are available in sizes and shapes that diamond is not.


While there are many benefits to gemstone engagement rings, there are also risks to consider before purchasing. Because gemstones aren’t as hard as diamonds, the rings may scratch and chip more easily. Couples can protect against this by choosing a hard gemstone in a protective setting.

Another issue to be aware of is that due to the unique shapes and colours of gemstones, it can be considerably more difficult to replace them in the event of a loss or breakage. Finding the exact colour can be tough, and you may find difficulty finding the exact measurements of your original stone.

You can protect yourself from this by having a gemologist appraise and colour grade the stone, to keep an exact record should an accident happen.

Are other gemstones durable enough?

You’ll often hear the phrase ‘diamonds are forever’, and this is because it is 10/10 on the Mohs scale. This means that diamond is literally the hardest substance known to man. There is nothing that can scratch or damage a diamond, except for another diamond.

Non-diamond gemstones simply aren’t this hard. However, neither is the glass on your phone screen, or even the bricks that make up your very home, so this isn’t to say that other gems can’t do the trick.

What is the Mohs Scale?

The Mohs Hardness Scale was developed to assess and rank the hardness of gemstones and minerals. It goes from 1 (talc) to 10 (diamond) and is incredibly useful when selecting a gemstone for an engagement ring. Dust, for example, is a 7/10, meaning it can scratch your gemstone.

So, when choosing a gemstone engagement ring, your best bet is to choose a gemstone of 7.5 and above. The closer you can get to 10, the more durable the ring.

Best gemstones for engagement rings


This is one of the most popular alternative engagement ring stones, and one of the best – as seen in this mid-century ballerina ring. Emerald sits at 7.5/10 on the Mohs Scale and comes in both light and dark shades of rich green. It is a Type III stone, which means it often shows eye-visible inclusions.

Couples choosing an emerald should take caution to make sure any inclusions (which are incredibly common) don’t reach the surface of the stone, as this may increase its risk for chipping. Also, make sure to choose an engagement ring setting that will protect any inclusions which could potentially put the stone at risk – Art Deco emerald rings may be a particularly daring choice.


This is an 8/10 on the scale, making it a good ring option. The most common colour of topaz today is blue, but it can also be found in colourless, pink, yellow and peach tones. Blue topaz comes in massive crystals, making it a great option for couples that want a bigger ring. When choosing a topaz ring, look for an eye-clean stone with a medium colour.


This comes in multiple colours with red, blue, pink and purple the most common. Although not commonly heard of, spinel makes a good engagement ring choice due to its 8/10 hardness, and vast array of colours. It is a Type II gemstone, meaning they often have some inclusions but can also be eye-clean. So, a couple choosing spinel should look for an eye clean stone in a colour that speaks to them.


This is a very shiny, eye-clean stone, as seen in this 20th century aquamarine ring. Like its sister stone, emerald, aquamarine is a 7.5/10. It comes in light, medium and darker blue; occasionally, it can contain a greenish hue reminiscent of the sea. Darker blue aquamarines will help to hide when the engagement ring is not sparkling clean, whereas light blue shows dirt and oil much more easily.


This has a particularly good hardness rating of 8.5, and a totally unique colour. In the light, alexandrite is green, but can change to red depending on how you look at it. They are Type II gemstones, meaning they will have some inclusions, but you can find eye-clean stones.

Sapphire and ruby

Sapphire and its sister ruby are the hardest non-diamond gems, sitting at 9 on the Mohs Scale. Red gems are rubies, all other colours are sapphires. They are Type II gems, but stones without inclusions are widely available. Art Deco sapphire rings and Art Deco ruby rings often display these beautiful gems in rich settings.

Rich medium tones are the most beautiful and valuable – as seen in this deep blue sapphire ring. Because of its superior hardness and vast array of colours, a sapphire/ruby is a great choice for a gemstone engagement ring. Many royal engagements have featured rings crafted with these stones.

This ruby and diamond crossover is striking and unique, with a blood red ruby the star of the show.

Worst gemstones for engagement rings


These are peachy-pink gems which are typically eye-clean, and they symbolise love and innocence. However, real life gets in the way of these gems and because of their light colour and lack of significant sparkle, morganite shows dirt and oil almost immediately. Even people who take regular care of their rings will experience this, due to things like handwashing, oil on skin, makeup etc. So, instead look for pink topaz, pink spinel or pink sapphire.


Pearls are beautifully romantic, but very, very soft at 2.5-4.5 on the scale. Normal damage includes loss of the pearl, dull spots where the nacre wears off, and chipping.


This is another very beautiful but soft gem, at 5.5-6.5 on the hardness scale. As a result, opal rings are not ideal for engagement rings. Couples should instead consider star sapphires, which are much harder and just as unique – this purple star sapphire ring is one of a kind.


Tanzanite has a beautiful blue-violet colour that is very uncommon in gems, however at a 6 on the Mohs Scale it’s a bad idea for an engagement ring. Instead, look for a violet spinel ring instead.


This is a rich purple stone that people adore for a unique engagement ring; however, at 7/10, amethyst has the same hardness as dust, and it will wear poorly over time. The stone will experience mini scratches until it is dull, which isn’t what you want for an engagement ring.