Why Focus on Diamond Hardness is Misleading

Posted by Khay Amani Oberon on

Hardness is only one of many measures of strength and durability that matter in a gemstone's longevity.

I think it's safe to say that nearly everyone has heard of the selling point about diamonds being the 'hardest substance on Earth' or something similar to this.

I would bet my left eyebrow (it's the better looking one, so you know I'm not messing around!) that very few people would be aware that this is not the be all and end all when it comes to a gemstone's durability.

In fact, I'd say that only gemologists and rock nerds would know that a better picture for assessing a gemstones properties is much more holistic and would include measures of strength, hardness, ductility and knowing how many planes of cleavage the material has.

Heck, even the temperature it formed at and melts at tells us a lot. Oops! I think my rock nerdiness is showing. 

Let's take it back a step.

Hardness is measured via the Mohs scale which you may have heard of and is a handy dandy 1 to 10 scale with 1 being the softest (talc) and 10 being the hardest (that would be diamond).

On the other hand, one measure of toughness is derived from the energy and force required to separate two joined crystalline particles within a stone. In other words, the force required to break it. As this isn't so easily explained, marketing teams don't know how to package this information for easy digestion.

Besides, why would the marketing team want you to know this? Their job is to have you buy more diamonds, not less. This measure of toughness has the humble yet regal nephrite jade hold an impressive value of up to 225,000. Whereas diamond, depending on which angle you hit it, tops out at a measly 8000.

Sapphire doesn't do much better, with a paltry 9000 on this scale.

Both of these measures are the reason why you can't easily scratch or abrade a diamond with friction (hardness) yet you could smash it quite easily into smithereens with a steel hammer (Toughness).

The fact that diamond has 4 planes of cleavage certainly doesn't help matters. The more planes a stone has, the higher the chance of impact damage.

And that's how it's possible to chip your diamond, especially around thin girdles and points like princess or marquise corners.

This very 'toughness' property is the reason why ancient Maori used New Zealand nephrite jade for both ceremonial weapons and... the 'not so ceremonial' weapons. Nephrite is a highly suitable material for bashing in your nemesis' (comparatively fragile) skull!

At this point I would like to express very clearly that there is no such 'perfect' stone that scores perfectly on all measures, why would you need it to be? I’m fairly sure you’re not looking to club someone’s head in with a big chunk of sapphire, if you are - wrong website bud. 

All gemstones have their pros and cons, so if  you pay too close attention to these stats alone the engineering advice will end up recommending you a piece of bubblegum stuck to a metal ring.

not the engagement ring she expects

Pretty sure this isn't the kind of ring she was expecting from you. Or is it? Did I mention that chewing gum kicks every gemstone’s butt  in measures for resilience qualities like ductility? Ha! Yeah, that's not a joke.


You’d be better off focusing on a couple of parameters really important to you like budget or colour and see how any particular stone's properties stack up as a whole for your particular lifestyle. You don't need to have a masters degree in mechanical engineering, after all we are talking about a piece of fine jewellery here, not a World War II army tank!

sherman world war 2 army tank

Pictured: Not an engagement ring.


Don't complicate things. The purpose of this entire post is simply to highlight the importance of looking at the whole picture, understanding that there is no 'magical stone' that will withstand meteor strike or nuclear fallout, and essentially not to fall for the sales-y hype built around the sale of one particular material.

vibranium, adamantium and starmetal Can you imagine the tools required to work with these metals?! 

This goes for metal too! I have spoken to many clients about their tradie husband-to-be potentially damaging their wedding ring and this worry leading them to tungsten or stainless steel. Potential de-gloving injury aside, what on earth are you doing with your hands that a gold or platinum ring can’t handle?! If it’s that dangerous, you shouldn’t wear a ring at all.

meat tenderizer


Gold or Platinum is metal. 

Your hand is made of meat. 

I feel like this image should be relevant.


We seem to forget that our grandparents and great-grandparents often lived very active hands on lives, often on the land, and wore gold wedding rings which did just fine. 

Like anything worthwhile in life, having a beautiful stone in a beautiful ring requires a bit of research and planning. 

Now go forth and buy the sparklies of your dreams!

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