Post # 1
Member
329 posts
Helper bee
I recently spoke with a custom jeweler about moissanite. Mind you, I know that this person has worked with moissanite so they arent simply an anti-moissanite person as far as I know. I’m not even buying moissanite but I have moissanite earrings and I’m a big fan of moissanite (it was cheaper for me to buy a vintage diamond ring). Anyways… my question… I’ve read differing things about moissanite “toughness” (different than hardness). Some sites I’ve read that its better than diamond in terms of toughness and on others I’ve read that its worse. This jeweler said that its worse and that the low toughness actually causes moissanite to “flake” off. I’m finding this hard to believe and don’t see any evidence of this online anywhere… anyone ever heard of that or know any reputable things about moissanite toughness?
Post # 3
Member
851 posts
Busy bee
@MsSunshineBee:
As far as Hardness goes, I think it’s well known on the board that Moissy is on the Moh’s scale at 9.25 — which means it can only be damaged or ‘flaked’ off by things harder than it. Glass is a 5.5 and a steel file is a 6.5. While these seem really close to each other, an 9 is twice as hard as an 8. A 10 is four times as hard as a 9.
Regarding toughness: Moissanite’s atomic structre does not have a direction of cleavage like diamond does. Diamond, while extremely hard can chip or shatter when struck by a hard object on its cleavage plane. Moissy isn’t indistructable by any means, but can take more damage in that regard.
I’m sure bees who have had their Moissy for years can chime in.
Post # 4
Member
724 posts
Busy bee
@MsSunshineBee: I just read the other day that someone’s moissanite shattered when they dropped their ring.
Post # 5
Member
329 posts
Helper bee
@beeintraining: My understanding is that hardness refers to the ability of things to scratch it. For some reason I’m having a hard time finding reliable info about toughness. Some sources say its tougher than diamond, others the way around. Youre right about the cleavage tho.
@JLR1982: I have seen reports on here of crushed moissanites from small incidents. Thats one reason why I was asking this.
Post # 6
Member
839 posts
Busy bee
They can flake off. We have had three flake apart. It is a synthetically made stone. Yes it exists in nature but is rare and mostly green and not clear. I have experience with the stone and in my opinion is much more destructable than diamond. A 9.25 is still worlds away from a 10. Think of it as having a hardness of a ruby or sapphire, it is absolutely possible. I am also not a fan of either diamonds or moissanite. I do wear a diamond but secretly wished for aquamarine.
Post # 7
Member
117 posts
Blushing bee
I recently read about how silica sand is mixed with carbon at extremely high temperatures to create the crystal. I believe it is then “grown”? It was interesting because it reminded me of tungsten carbide, which is tungsten powder mixed with carbon. We have tungsten carbide rings, so I remember researching how they can shatter or chip, and remember reading not to leave them in an ultrasonic cleaner for an extended time (loses cohesion??). I wondered if it’s kind of the same principle? I have moissanite, and it continues to fascinate me. I’d love to be steered in the right direction about this!
Post # 8
Member
329 posts
Helper bee
@crescent: interesting! Im fascinated by moissanite too. I have earrings and have considered upgrading my .16 diamond to a moissanite one day so I’m really curious about this flaking business.
Post # 9
Member
1695 posts
Bumble bee
SiC (moissanite) is one of the most atomically stable crystal structures we know of. It is only about 30% as hard as a diamond, but the indistinct cleavage planes along with stronger atomic bonding make it an inherently tougher material. That isn’t to say there are not cases where there could be an unseen flaw in a stone that causes fracturing if hit right, but that’s a very rare scenario.
Now, currently the stones produced by C&C all have these ridiculously thin girdles (where the pavilion meets the crown) which means that the girdles are more prone to chipping than a stone cut with a medium/thick girdle. This is not an inherent problem with SiC, but a created one due to the cut.
I’ve been reading up on and researching SiC for years, and this is the first time I’ve EVER heard of anyone claiming “flaking” of the stone, which is nonsense.
Post # 10
Member
329 posts
Helper bee
@MrsCassie: best answer yet, that makes a lot of sense!
Post # 10
Member
4 posts
Wannabee
May I weigh in on this old thread? Sorry to resurrect it, but this was the ONLY mention I could find online about this matter. I have 40+ Moissanites in my ring. It is a remake of my original because my original was cheaply made and the stones started falling within two months. Now my remake is also loosing stones because a few are fractured (me vs filing cabinet, cabinet won). I’ve noticed the ones that are fractured do flake if I scratch it with my nail (bad bad bad me). When I got my hand caught on the cabinet, one stone lost quite a chunk and when I poked it because I noticed it was definately less fiery than the others it “flaked”. I put that in quotes because all my Moissanites except the center stone are lil mellies and perhaps the appearance of flaking is due to their tiny size. My jeweler is NOT happy and is hard pressing me to replace my small moissanites with diamonds (for $1300 after I already had it custom made this summer). *sigh*. I came to the Internet searching for answers to my dilemma . I can tell there is one more bound to fall out it has taken a whitish appearance the other one had before it flaked into pieces. I just don’t know if that. 5 moh hardness is going to make a difference. I mean we are talking about a sudden force, even diamonds would fracture under that pressure I assume.
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