Coloured Gems Vs Diamonds on the Moh Scale of Hardness

Coloured Gems Vs Diamonds on the Moh Scale of Hardness

When it comes to “durability”, diamonds might be the first to pop in mind. This is mostly due to an incredibly successful marketing campaign from 1948 that famously proclaimed “A Diamond is Forever”. A powerful statement that has continued to be widely spread ever since. However, this was a long time ago, and a great deal of new information has emerged since then.

Diamonds are measured at 10 on the Mohs hardness scale and can only be scratched by another diamond. However, there are a vast array of coloured gemstones that measure highly on the Moh scale too! Let’s explore a few!

Colourless and Yellow and Pink Diamond Rings Made to Order

Custom-made white, yellow and pink diamond rings

When you choose something as emblematic as an engagement ring, the right gem is likely to cause an emotional response. You should feel a connection to your piece, and naturally, the first attribute to impact you will be visual. However, there are other relevant factors to be weighed in, such as a gem’s wearability, clarity, and optical performance. The following five coloured gems combine excellent properties, beautiful colours, and stunning performance.


Their durability, rarity and mesmerising fiery glow make them well worthy of the crown as the “Queen of coloured gems”. Rubies might be the most valuable variety of the corundum mineral species – a family that also includes sapphires. The quintessential symbol for red is a 9 on the scale of hardness and has a specific gravity of 3.9 to 4.1; making it a remarkable choice for daily-wear. If well cared for, a ruby certainly is forever.

Bespoke Ruby Ring

Enchanting bespoke ruby ring with diamonds

Bespoke Ruby Ring

A lively custom-made ruby ring with a halo of coloured gems and diamonds


They offer a diverse colour range, including glistening tones of green, yellow, blue, orange, red, purple, and pink! Traditionally, topaz was favoured as a golden yellow stone. Though, nowadays, blue probably ranks as the most sought after hue. They’re an 8 on the hardness scale, meaning they have great resistance to scratching. Combine these attributes with phenomenal colours to choose from and you’ll find a very strong candidate for your top pick!

Custom-made blue topaz ring

Custom-made blue topaz ring with diamonds

Yellow topaz bespoke ring with mother-of-pearl

Imperial topaz bespoke ring with mother-of-pearl


Their enchanting light blue colouring is enough reason to fall in love with aquamarines. But thankfully, they also present some other amazing qualities! They’re usually encountered without any inclusions, are ‘eye clean’, meaning pretty flawless. They are a 7.5 to 8 on the hardness scale. As long as treated with care, an aquamarine ring is a great pick!

Bespoke Aquamarine ring

Bespoke Aquamarine ring flanked by diamonds




If variety is what you’re after, look no further! Yellow, green, orange, pink… and even bi-coloured! There is an entire rainbow of shades to select from when it comes to this much beloved gem. Tourmalines rank 7 to 7.5 on the Mohs scale, so are considered fairly tough. Some multi-coloured species are acquainted as a representation of two souls becoming one. While the rare and incredibly praised Paraíba is thought to encourage love and make a stunning choice for an engagement ring!


Bespoke lagoon tourmaline ring

Bespoke lagoon tourmaline ring with tsavorites and diamonds


Alongside their fiery sister ruby, sapphires are the hardest non-diamond gems available at 9 on the Mohs hardness scale. Together with their impressive array of colours, you’ll easily understand why they’re so desired! Sapphires are amazing stones for daily use.

Blue sapphire custom-made ring

Blue sapphire custom-made ring with diamonds

Bespoke purple sapphire ring

Bespoke purplish-pink sapphire ring with diamonds