Designing a bespoke engagement ring is a deeply personal and meaningful occasion and opting for a birthstone engagement ring has become a popular choice in South Africa. Incorporating a birthstone into your engagement ring is an easy way to add a touch of sentimentality and uniqueness to your ring – but it’s not necessarily the most practical of options.

Many people attach significance to birthstones. Depending on your belief systems, they could be traced back to the Biblical book of Exodus where the Breastplate of Aaron was decorated with 12 gemstones. This idea was then extrapolated to the 12 signs of the Zodiac and 12 months of the year.

However, it is worth noting that the modern list of birthstones, the list that is marketed today (and yes, it is marketing), was only conceptualized in 1912 by the (American) National Association of Jewelers (now known as “Jewelers of America”). You could consider it this way – a group of men got together and arbitrarily allocated each month a gemstone to be promoted as the birthstone for that month.

The birthstone list was updated in 1952 by a different trade association (The Jewelry Industry Council of America) with the addition of alexandrite (June), pink tourmaline (October) and citrine (November). In 2002, The American Gem Trade Association (yet another trade organization) added tanzanite as the birthstone for December. In 2016, spinel was added as an additional August birthstone and in 2021 jewellery and gemstone associations in Japan added 10 more birthstones to the list.

By now, it should be clear that the list of birthstones has no real long-term historical context and has been amended and added to randomly over the last 120 years. Many people have created their own significance around gemstones and birthstones, and we respect each person’s belief in that regard.

Should you wish to create a birthstone engagement ring, it’s worth noting that not all gemstones are hard or durable enough for daily, long-term use in an engagement ring. So, with that in mind, let’s look at the best, and the worst gemstones to use in a birthstone engagement ring.

The 3 best birthstones for an engagement ring:

Given that an engagement ring is intended to be worn daily for the rest of your life, you want a main gemstone that is hard, durable, and resistant to wear and tear. All gemstones have a hardness value according to Moh’s hardness scale and diamonds, ruby and sapphires are the hardest gemstones on the scale.

Moh's Hardness scale

Moh’s hardness scale, which plots the hardness of all gemstones. Note how the sale is exponential, so diamond is 3 times harder than ruby and sapphire.

Even without clever advertising, (De Beers hired New York advertising agency N.W. Ayer in 1938 to promote the sale of diamonds), diamonds are the most practical engagement ring gemstone. They have a hardness of 10 out of 10 on the hardness scale and are durable and exceptionally robust.

Ruby and sapphire are the same mineral, corundum, and rate at 9 out of 10 on the hardness scale. As such, they are second only to diamonds in terms of practicality for birthstone engagement rings.

Diamonds (April), rubies (July) and sapphires (September) are thus the three best birthstones to incorporate in an engagement ring as either the main gemstone or side gemstones.

Diamond birthstone engagement ring

There’s a reason that diamonds are still popular in engagement rings. They’re the hardest and most durable gemstone we know.

The 4 worst birthstones for an engagement ring:

If you (or your significant other) were born in June, October or December, you’d be best avoiding these month’s birthstones in an engagement ring. Technically, June has three birthstones (remember how many associations have been involved in putting the birthstone list together?), namely pearl, alexandrite and moonstone.

Pearls, whilst beautiful, are not technically gemstones, but are instead comprised of layers of microcrystalline calcium carbonate. Grown inside of molluscs such as oysters, they are prized for their unique lustre. Available in a variety of colours (created by the use of dyes), they can be dissolved in vinegar and have a hardness of only 2.5 to 4.5 on Moh’s hardness scale. This softness means they are susceptible to being easily scratched or abraded and they can be discoloured by perfume, hair spray and cosmetics.  We highly recommend avoiding the use of pearls in engagement rings.

Pearl birthstone ring

We designed a pink topaz and pearl ring for a client, with a clear message that it is not suitable for everyday wear due to the softness of the pearls. Instead, we recommended it as a piece to be worn on special occasions.

Moonstone is the gemstone version of the mineral feldspar and is known for its adularescence, which provides its milky, bluish appearance. Chatoyancy, or the “cat’s eye effect”, visible in a bright streak appearing through the stone, is another characteristic that makes moonstone popular. Moonstone has a hardness of 6 on the hardness scale, so again, it’s not a gemstone durable enough for use in an engagement ring.

Opal is October’s birthstone and of all the gems to avoid in an engagement ring, this is top of our list. Opal is an amorphous form of silicate and is classified as a mineraloid because it has no distinct crystal structure. With a water content that ranges from 3% to 21% (by weight), opal has a hardness of 5 to 6.5 and is exceptionally susceptible to damage and extreme changes in heat. Would we recommend it for a birthstone engagement ring? Never.

You may recall from earlier in this article that tanzanite was added as December’s birthstone in 2002. Tanzanite is a unique and beautiful gemstone but has a hardness of only 6.5 to 7 on Moh’s scale. You can read up here as to why we think tanzanite engagement rings are a terrible idea.

Tanzanite birthstone engagement ring

The client who ordered this tanzanite ring is aware that, despite it being an engagement ring, it requires careful handling and should ideally not be worn on a daily basis.

Wear these birthstones with caution:

Emeralds are beautiful green gemstones that have a hardness of 8 out of 10. On paper, this is a good-sounding number but whilst hard, emeralds are not durable and can be easily chipped, broken or cracked. For this reason, we encourage caution when choosing an engagement ring with emerald as the main gemstone.

Emerald engagement ring

Emeralds in engagement rings should always be treated with the utmost care.

Garnet, aquamarine, topaz, tourmaline, spinel, citrine and zircon all range from 7 to 8 in hardness and are therefore relatively practical but perhaps best suited to side stones in an engagement ring.

Diamond and aquamarine birthstone ring

This client wanted to incorporate aquamarine as a birthstone in their engagement ring. After discussing with us, they opted for a diamond centre and aquamarine accents.

Alexandrite has a hardness of 8 out of 10 and is quite hard and durable but is exceptionally rare and exceptionally expensive. It’s generally only available in relatively small sizes and much of the alexandrite you see advertised online is synthetic corundum (i.e. synthetic sapphire) and is not genuine alexandrite at all.

Can birthstones add significance and meaning to your engagement ring? Absolutely. Just be aware that they’re not all as practical as each other in engagement rings and some birthstones are best suited to setting in pendants or earrings. If you’re looking for a bespoke engagement ring and aren’t sure what would be best for you or your partner, give Katannuta Diamonds a call and we’ll help you create a magnificent ring.