If moissanite is almost as hard as diamond why isn’t there moissanite blades if moissanite is cheaper?
In: 4910
Friendly reminder that diamond is the 4th most common gemstone.
They are beat out by:
1. Quartz
2. Amethyst
3. Garnets
4. Diamonds.
ETA: https://rockseeker.com/most-common-gemstones/
Silicon carbide (moissanite) is indeed very hard and applicable for industrial use, but is rare. Yes, you can make it in a lab but industrial scale diamonds (dirt cheap compared to jewelry diamonds) are overwhelmingly plentiful in the ground and do not require any lab-type environments to produce.
You can buy packs of diamond bits for little more than tungsten carbide bits from suppliers and they supply is immense.
Silicon carbide (moissanite) is indeed very hard and applicable for industrial use, but is rare. Yes, you can make it in a lab but industrial scale diamonds (dirt cheap compared to jewelry diamonds) are overwhelmingly plentiful in the ground and do not require any lab-type environments to produce.
You can buy packs of diamond bits for little more than tungsten carbide bits from suppliers and they supply is immense.
Silicon carbide (moissanite) is indeed very hard and applicable for industrial use, but is rare. Yes, you can make it in a lab but industrial scale diamonds (dirt cheap compared to jewelry diamonds) are overwhelmingly plentiful in the ground and do not require any lab-type environments to produce.
You can buy packs of diamond bits for little more than tungsten carbide bits from suppliers and they supply is immense.
Lots of people talking about silicon carbide (or artificial diamond) being used as an industrial abrasive, as a grit coat on circular saws, etc. All true enough, but OP said “blades.”
Diamond is very very hard, but “hard” is not the same thing as “tough.” Very hard things are also very brittle. Metal used for blades is a compromise between being hard enough to hold a good edge, but soft enough that it can flex or get dull under strain instead of breaking. (You can always resharpen a dulled edge.) If you made a knife or a saw or whatever out of *solid* diamond/moissanite/silicon carbide, it would be sharp as all hell, but if you tried to cut anything harder than raw beef with it, it would shatter into pieces. It might even shatter cutting the beef if you twisted it the wrong way.
Now, there *are* applications for ultra-hard, ultra-sharp blades. The main one I know of is surgery, especially surgery on very delicate things like eyeballs. If you’re only cutting into meat, and you’re being very slow and precise about it, ultra-hard blades are ideal. It turns out one of the best materials for that is obsidian. Obsidian scalpels are about the sharpest things that humans make on a regular basis. A diamond or silicon carbide scalpel *would* probably do the job, but it would be difficult if not impossible to make a single, flawless crystal even big enough to be a scalpel blade, whereas there are whole mountains full of obsidian just waiting to be chipped and sharpened. A caveman could do it, and cavemen literally did before we discovered metal.
It’s not almost as hard. Diamond has a hardness of 100 GPa. Silicon carbide (which is the compound in the mineral Moissanite) has a hardness between 20 and 30 GPa, depending on the load and purity.
People think some minerals, like Corundum (alumina) and Moissanite (SiC), are almost as hard as diamond as they have a hardness of 9 and 9.25, respectively, on the [Mohs hardness scale](https://en.m.wikipedia.org/wiki/Mohs_scale). However, the Moh’s scale is [not linear](https://geology.com/minerals/photos/mohs-vickers-comparison-scale.gif), especially towards the higher end.
Lots of people talking about silicon carbide (or artificial diamond) being used as an industrial abrasive, as a grit coat on circular saws, etc. All true enough, but OP said “blades.”
Diamond is very very hard, but “hard” is not the same thing as “tough.” Very hard things are also very brittle. Metal used for blades is a compromise between being hard enough to hold a good edge, but soft enough that it can flex or get dull under strain instead of breaking. (You can always resharpen a dulled edge.) If you made a knife or a saw or whatever out of *solid* diamond/moissanite/silicon carbide, it would be sharp as all hell, but if you tried to cut anything harder than raw beef with it, it would shatter into pieces. It might even shatter cutting the beef if you twisted it the wrong way.
Now, there *are* applications for ultra-hard, ultra-sharp blades. The main one I know of is surgery, especially surgery on very delicate things like eyeballs. If you’re only cutting into meat, and you’re being very slow and precise about it, ultra-hard blades are ideal. It turns out one of the best materials for that is obsidian. Obsidian scalpels are about the sharpest things that humans make on a regular basis. A diamond or silicon carbide scalpel *would* probably do the job, but it would be difficult if not impossible to make a single, flawless crystal even big enough to be a scalpel blade, whereas there are whole mountains full of obsidian just waiting to be chipped and sharpened. A caveman could do it, and cavemen literally did before we discovered metal.
It’s not almost as hard. Diamond has a hardness of 100 GPa. Silicon carbide (which is the compound in the mineral Moissanite) has a hardness between 20 and 30 GPa, depending on the load and purity.
People think some minerals, like Corundum (alumina) and Moissanite (SiC), are almost as hard as diamond as they have a hardness of 9 and 9.25, respectively, on the [Mohs hardness scale](https://en.m.wikipedia.org/wiki/Mohs_scale). However, the Moh’s scale is [not linear](https://geology.com/minerals/photos/mohs-vickers-comparison-scale.gif), especially towards the higher end.
Lots of people talking about silicon carbide (or artificial diamond) being used as an industrial abrasive, as a grit coat on circular saws, etc. All true enough, but OP said “blades.”
Diamond is very very hard, but “hard” is not the same thing as “tough.” Very hard things are also very brittle. Metal used for blades is a compromise between being hard enough to hold a good edge, but soft enough that it can flex or get dull under strain instead of breaking. (You can always resharpen a dulled edge.) If you made a knife or a saw or whatever out of *solid* diamond/moissanite/silicon carbide, it would be sharp as all hell, but if you tried to cut anything harder than raw beef with it, it would shatter into pieces. It might even shatter cutting the beef if you twisted it the wrong way.
Now, there *are* applications for ultra-hard, ultra-sharp blades. The main one I know of is surgery, especially surgery on very delicate things like eyeballs. If you’re only cutting into meat, and you’re being very slow and precise about it, ultra-hard blades are ideal. It turns out one of the best materials for that is obsidian. Obsidian scalpels are about the sharpest things that humans make on a regular basis. A diamond or silicon carbide scalpel *would* probably do the job, but it would be difficult if not impossible to make a single, flawless crystal even big enough to be a scalpel blade, whereas there are whole mountains full of obsidian just waiting to be chipped and sharpened. A caveman could do it, and cavemen literally did before we discovered metal.
It’s not almost as hard. Diamond has a hardness of 100 GPa. Silicon carbide (which is the compound in the mineral Moissanite) has a hardness between 20 and 30 GPa, depending on the load and purity.
People think some minerals, like Corundum (alumina) and Moissanite (SiC), are almost as hard as diamond as they have a hardness of 9 and 9.25, respectively, on the [Mohs hardness scale](https://en.m.wikipedia.org/wiki/Mohs_scale). However, the Moh’s scale is [not linear](https://geology.com/minerals/photos/mohs-vickers-comparison-scale.gif), especially towards the higher end.
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