# Diamonds Vs. Cubic Zirconium **URL:** \ **Category:** Factual Questions\ **Created:** [June 4, 2002, 6:11pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347 "2002-06-04T18:11:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [June 4, 2002, 6:11pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/1 "2002-06-04T18:11:01Z")
Can a layperson distinguish cubic zirconium from a real diamond? What about these newer ‘synthetic’ diamonds?? If you can’t tell the difference, why would anyone pay more? Thanks. ---
**Author:** ![scout1222](https://avatars.discourse-cdn.com/v4/letter/s/34f0e0/32.png) [@scout1222](https://boards.straightdope.com/u/scout1222)\ **Post date:** [June 4, 2002, 7:00pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/2 "2002-06-04T19:00:47Z")
I personally cannot tell the difference. And I suspect most people can’t. I bought a pair of fake diamond earrings from Target - 1 carat jobbies. People frequently commented on them, oohing and ahhing. They thought they were real. I was relishing that I paid like thirty bucks for something others thought was priceless. I’m all about fakes that look real, so generally, if I wore jewelry, I’d be perfectly happy to wear (decent quality) fakes. ---
**Author:** ![tramp](https://avatars.discourse-cdn.com/v4/letter/t/4491bb/32.png) [@tramp](https://boards.straightdope.com/u/tramp)\ **Post date:** [June 4, 2002, 7:07pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/3 "2002-06-04T19:07:21Z")
I can sure as shit tell. A diamond, even a crappy one, has more brilliance than the best Suzanne Somers QVC Pink Ice CZ crapola. If you seriously can’t afford a diamond, there is a natural stone called moisonite (sp?) which actually has even more brilliance than a diamond. The bad part about moisonite (again sp?) is that it can’t be cut into stones less than a carat. So smaller accent stones are out. Moisonite looks a helluva lot more like a diamond than CZs. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [June 4, 2002, 7:13pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/4 "2002-06-04T19:13:10Z")
A layperson probably can’t tell, I think you might have to weigh it since the specific gravity is different than diamonds. Diamonds are one of those funny things. They have no intrinsic value, it’s just whatever you think they’re worth. So you would pay more because you would _just **know** _ that it’s a real diamond. IMHO the reason that diamonds are valuable is that they cost so much, if you catch my drift. ---
**Author:** ![LiquidLobotomy](https://avatars.discourse-cdn.com/v4/letter/l/898d66/32.png) [@LiquidLobotomy](https://boards.straightdope.com/u/LiquidLobotomy)\ **Post date:** [June 4, 2002, 7:13pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/5 "2002-06-04T19:13:22Z")
Yes you can. Turn the diamond upside down and put it on a sheet of paper (with writing on it.) If you can read the writing or see the letters, then it’s fake. ---
**Author:** ![LiquidLobotomy](https://avatars.discourse-cdn.com/v4/letter/l/898d66/32.png) [@LiquidLobotomy](https://boards.straightdope.com/u/LiquidLobotomy)\ **Post date:** [June 4, 2002, 7:15pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/6 "2002-06-04T19:15:20Z")
Actually Cooking, it’s a supply and demand issue. Although technically diamonds aren’t rare, the owners (predominately DeBeers) cut off the supply and drive the prices up. ---
**Author:** ![tramp](https://avatars.discourse-cdn.com/v4/letter/t/4491bb/32.png) [@tramp](https://boards.straightdope.com/u/tramp)\ **Post date:** [June 4, 2002, 7:16pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/7 "2002-06-04T19:16:15Z")
Oh believe me boys, a girl can tell. ---
**Author:** ![Kamandi](https://avatars.discourse-cdn.com/v4/letter/k/5daacb/32.png) [@Kamandi](https://boards.straightdope.com/u/Kamandi)\ **Post date:** [June 4, 2002, 7:37pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/8 "2002-06-04T19:37:53Z")
> [@](#): > > \*Originally posted by Surreal \* > \*\*Can a layperson distinguish cubic zirconium from a real diamond? What about these newer ‘synthetic’ diamonds?? > > If you can’t tell the difference, why would anyone pay more? > > Thanks. \*\* Trust me, kid, don’t put a cubic in an engagement ring. It may be cheaper up front, but you’ll pay dearly down the road. She _will_ find out. ---
**Author:** ![CheapBastid](https://avatars.discourse-cdn.com/v4/letter/c/8baadc/32.png) [@CheapBastid](https://boards.straightdope.com/u/CheapBastid)\ **Post date:** [June 4, 2002, 7:46pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/9 "2002-06-04T19:46:06Z")
Looks to be [pretty difficult](http://www.foreverwed.com/jewelry/how_to_tell.htm). ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 4, 2002, 7:46pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/10 "2002-06-04T19:46:18Z")
I can usually tell the difference. If a CZ is put side byt side with a diamond I bet I could pick the diamond 95% of the time. I recently bought my wife a pair of diamond earrings for her birthday but she decided they looked too small (3/4 carat). We went back to the store intent on getting a carat but she was floored by the price (which made me happy…she had never really priced diamonds before and now she knows what that ring on her finger is likely worth). Instead she decided a cheap, big CZ, looked better on her than an expensive, small diamond. Still, everytime I look at them I can’t help but think how flat they look. You can test any of this for yourself. Next time your near a jewelry store ask them to place a CZ and diamond side-by-side and I’ll bet you immediately notice the difference. As for synthetic diamonds realize that they are real diamonds except that they are made in a machine instead of underground. However, I am not aware of any synthetic diamonds used for jewelry. It takes a few days to grow a diamond a few millimeters across. To get a gem sized diamond out of this process I think the resulting diamond would cost more to manufacture than just buying a real diamond. Synthetic diamonds are mostly used in industry as they have excellent cutting and polishing properties. For industry diamond ‘dust’ usually does the job nicely and is cheaper than getting real diamonds. ---
**Author:** ![tramp](https://avatars.discourse-cdn.com/v4/letter/t/4491bb/32.png) [@tramp](https://boards.straightdope.com/u/tramp)\ **Post date:** [June 4, 2002, 8:02pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/11 "2002-06-04T20:02:52Z")
I think the big deal with synthetic diamonds is that they can be made cheaper and exactly the same quality than a mined diamond. And DeBeers, well they aren’t too thrilled with that so they somehow, if I recall correctly, put the kibosh on synthetic diamonds. ---
**Author:** ![CheapBastid](https://avatars.discourse-cdn.com/v4/letter/c/8baadc/32.png) [@CheapBastid](https://boards.straightdope.com/u/CheapBastid)\ **Post date:** [June 4, 2002, 8:16pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/12 "2002-06-04T20:16:34Z")
Gotta love that [Moissanite](http://cbc.ca/consumers/market/files/scams/moissanite/index2.html). ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [June 4, 2002, 8:40pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/13 "2002-06-04T20:40:56Z")
Hey, why let a few facts get in the way of a good conspiracy theory, right? There are dozens of companies that make synthetic diamonds, as a few seconds with almost any search engine will tell you. You’ll quickly find links to synthetic “gem-grade” diamonds, in sizes at least as large as 1 carat. Not being a gemologist, I can’t tell help you separate the hype from fact with regard to comparisons between natural and synthetic diamonds. With regard to the practical value of diamonds, there are many industrial uses. Aside from the aforementioned cutting and grinding uses, my father-in-law designed a heat-sink for DEW-line radar systems using diamonds because of their fantastic heat transfer properties. None of the conventional heat sink materials at the time were adequate, but diamond worked well. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [June 4, 2002, 8:41pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/14 "2002-06-04T20:41:31Z")
**Whack-a-Mole** - “_Instead she decided a cheap, big CZ, looked better on her than an expensive, small diamond. Still, everytime I look at them I can’t help but think how flat they look_” Well, I suppose that could be due to the inferior material properties of the CZ, but it could also be due to bias. Since you _know_ they aren’t real, everytime you look at them you are reminded of that fact, and this could affect your perception in a negative way. I’m gonna have to do a side-by-side comparison to make sure, like you suggested. It must be done double-blind, too- same size, same lighting, etc. ---
**Author:** ![tramp](https://avatars.discourse-cdn.com/v4/letter/t/4491bb/32.png) [@tramp](https://boards.straightdope.com/u/tramp)\ **Post date:** [June 4, 2002, 8:45pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/15 "2002-06-04T20:45:01Z")
> [@](#): > > \*Originally posted by CheapBastid \* > \*\*Gotta love that [Moissanite](http://cbc.ca/consumers/market/files/scams/moissanite/index2.html). \*\* I _told_ you moissanite was good stuff… ---
**Author:** ![Spectre\_of\_Pithecanthropus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spectre_of_pithecanthropus/32/12343_2.png) [@Spectre\_of\_Pithecanthropus](https://boards.straightdope.com/u/Spectre_of_Pithecanthropus)\ **Post date:** [June 4, 2002, 9:34pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/16 "2002-06-04T21:34:32Z")
Square or rectangular step cut CZ’s look noticeably less brilliant than diamonds, but IMO round and oval brilliant-cut CZ’s look very convincing. CZ’s fail rather more noticeably when they are used to imitate colored stones. Usually this is because they are _too_ brilliant. An aqua- colored CZ is way more brilliant than a genuine aquamarine, the beryl gemstones being characterized by a more subdued luster than most gemstones (or we could uncharitably call it a “glassy” luster). Same with emeralds. ---
**Author:** ![scout1222](https://avatars.discourse-cdn.com/v4/letter/s/34f0e0/32.png) [@scout1222](https://boards.straightdope.com/u/scout1222)\ **Post date:** [June 4, 2002, 9:50pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/17 "2002-06-04T21:50:40Z")
Well, apparently I’m just an ignorant rube. I guess everyone else can tell but me. Of course, I’m not a big jewelry wearer, so I’m probably not your best source for info. Carry on… ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [June 4, 2002, 10:16pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/18 "2002-06-04T22:16:15Z")
Supposedly, the Russians have come up with an inexpensive method of making synthetic diamonds by zapping graphite with high voltage that produces synthetics that the experts have difficulty recognizing as such. ---
**Author:** ![racinchikki](https://avatars.discourse-cdn.com/v4/letter/r/eada6e/32.png) [@racinchikki](https://boards.straightdope.com/u/racinchikki)\ **Post date:** [June 4, 2002, 10:38pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/19 "2002-06-04T22:38:12Z")
My engagement ring’s a CZ (I didn’t see the point in waiting several years until he can afford a diamond; hell, I don’t see the point in having a diamond at all, personally - if he was gonna spend several thousand on a gift for me I’d ask for an engagement _car_). It’s about .75 ct size. When it’s clean (it picks up grime pretty readily, so I have to clean it every few days; also the silver setting tarnishes very quickly), it’s very convincingly diamondesque. It’s fooled several people, but only laypeople - I’m confident a jeweler or even a common rube who’s more knowledgable about gemstones would be able to tell at a glance that it’s a CZ, even on a good day. ---
**Author:** ![LolaCocaCola](https://avatars.discourse-cdn.com/v4/letter/l/7cd45c/32.png) [@LolaCocaCola](https://boards.straightdope.com/u/LolaCocaCola)\ **Post date:** [June 4, 2002, 10:50pm UTC](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347/20 "2002-06-04T22:50:14Z")
Diamonds are the hardest natural substance known to man. Not sure if it’s a real diamond? Try cutting class with it; a real diamond can, a CZ can’t. [Next page](https://boards.straightdope.com/t/diamonds-vs-cubic-zirconium/112347.md?page=2)