Talk:Diamond simulant

Untitled

Moved from Talk:Diamond

Cubic zirconia

Cubic Zirconia - $5/carat - can get scratched, over time loses it's lustre, doesn't fool experts.

Statements where reasonable people may disagree

• Cubic Zirconia doesn't sparkle as much.
  • Perhaps some brands of cubic zirconia don't sparkle as much as ideal cut diamonds. Other brands cut to different proportions, or to more precise proportions, to make sparkly CZs.
  • Stick to the objective characteristics (index of refraction, dispersion, etc.), and add explanations to those.

New technology has produced a new breed of Russian CZ which are far superior to older versions. They look and feel more optically correct to a perfect diamond.

~Ender

Moissanite

Moissanite - $300/carat - almost as hard as diamond, more brilliant

• Moissanite is not nearly as hard as diamond. Remember, the Mohs scale of mineral hardness is not linear. Though Moissanite falls at about 9 on Mohs, and diamond at 10, diamond is actually about four times harder than Moissanite. See this page for a decent explanation of scales of mineral hardness: http://www.inlandlapidary.com/user_area/hardness.asp

Actually, the scale is exponential; The Mohs scale between 9 and 10 is 140 times difference in hardness, not 4. Simulated moissanite (synthetic silicon carbide) is not even close to being as hard as a diamond.

~Ender

Mohs scale of mineral hardness disagrees, listing the difference at 4 times. Slightly off topic, I find the article as a whole to be very biased, in subtle language, towards conveying an impression of diamonds as the perfect gemstone. E.g. the part where less sparkly gemstones are 'lifeless' and sparkly-er gemstones are 'tacky and unreal'. So... diamonds are just right? Are we playing Goldilocks here?

~ Wahming (talk) 20:04, 20 September 2015 (UTC)

Statements where reasonable people may disagree

• Moissanite fools many professionals.
  • The gem laboratories have offered training to teach the differences between moissanite and diamond.

~ender 2004-09-04 MST 19:22

• • Moissanite would not fool any gemologist that knows anything about the material. Off the top of my head, birefringence is a dead giveaway. The excessive "brilliance" is also significant.

Moissanite was never offered by Charles & Colvard as a diamond simulant. The designation of Moissanite as a diamond simulant is incorrect.

It does not matter what Charles and Colvard market moissanite as - it has been perceived by the market as a simulant of diamond, white clear stones of high refraction that are marketed as an alternative for Engagement ring major stones are certainly a diamond alternative and simulant. Additionally, charles and colvard are a primary supplier to secondary suppliers who market the stone in their own way. That is what matters. SauliH 02:07, 31 January 2007 (UTC)

The Mohs scale is a measure of the resistance of a jewel to abrasions. Thus the Mohs scale does provide a useful measure for all intents and purpose as criteria used in the purchase of jewelry. In addition Moissanite is so hard that it is used as anvils by MIT.

This was taken from intelproplaw.com which further explains this topic. If this was inaccurate, it would have been pulled from the site. Any thoughts?:

1. It's not moissanite at all, it's faceted synthetic silicon carbide, also, known as simulated moissanite. Most gemologists agree now that it is a stretch calling synthetic silicon carbide even synthetic moissanite. Natural moissanite is so rare; few people have ever seen any, much less the ability to copy in the lab. Another more proper name for this silicon carbide is carborundum, not moissanite.

All moissanite is silicon carbide, but not all silicon carbide is moissanite. The mineral word “moissanite” cannot be trademarked and has never been by anyone.

2. Henri Moissan did not discover silicon carbide, natural or synthetic. The discovery of silicon carbide predates him by many years. He was credited with a scientific discovery in the Diablo Canyon and that is all. His discoveries have nothing to do with simulated moissanite or the silicon carbide produced by Cree.

3. There is no meteoric origin to today's simulated moissanite or faceted synthetic lab created silicon carbide. none whatsoever. see #2.

4. C&C's patents indicate relative hardness of 8.5-9.0, not 9.25 (does not exist on any scale, especially the most common, mohs). Also, no mention of the term moissanite, desire to produce synthetic or simulated moissanite or any reference to sell moissanite in patents. The patents only protect, faceting sythetic silcon carbide (a diode byproduct from cree) into the most common diamond shapes. Therefore, simulated moissanite is not the second hardest substance on earth or used in jewelry. The 9.25 number touted is completely fictional, non-existent. Check the patents out for yourself at www.uspto.gov patent #5,723,391 and 5,762,896

5. Simulated moissanite is truly "green or yellow" tinted in natural sunlight and stuller says it is rarely near colorless.

6. Because it is tinted c&c is attempting to move it as a jewel in it's own right even though every retailer in the world sells as a diamond substitute or simulant to the consumer and in wedding jewelry (a substitute for diamond). Even the founder, Jeff Hunter, acknowledges it as a diamond substitute in the following article and in his patents;

In article from the National Jeweler friday, october 1, 1999

7. It's not a gemstone but a jewel (c&c calls it a jewel too, ftc issue), because it has absolutely no precious or even semi-precious qualities whatsoever. It comes from very common and abundant silicon manufactured by Cree in North Carolina in their “light emitting diode” (LED) manufacturing plant.

8. It does chip and break with high frequency by the consumer because is so stiff, not tough.

9. Faceted silicon carbide is the most expensive lab created jewel used in jewelry today. Why? High overhead to produce and distribute and millions spent on marketing. For price paid, it is not superior to cubic zirconia.

10. The GIA (gemological institute of america), the most respected educational institution today calls simulated moissanite (faceted silicon carbide), a “diamond simulant” (another term is fake diamond).

11. The product sold and distrubited by Charles & Colvard, is nothing more than a "diode" by-product manufactured by Cree in North Carolina and faceted to look like a diamond (same shapes & similar cuts). Cree is one of the largest producers of silicon carbide light emitting diodes.

Hope this helps further discussion. By the way, the above points have never been properly refuted by anyone.

Summary table

Moved to main article

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This summary table is an excellent idea. (Thanks Jasper!) I've filled in the missing data; should we add anything else before introducing it into the article? -- Hadal 05:28, 21 Mar 2005 (UTC)

My pleasure.

Some things to think about before adding the table to the article:

• Should we add whether each material is natural, synthetic, artificial, or both natural and synthetic? (Perhaps a row of the table after diamond could be "Synthetic and artificial simulants:", and a row of the table after Moissanite could be "Natural simulants:".)
  • Done.
• The article should note that "The index(es) of refraction column shows one RI for singly refractive substances, and a range for doubly refractive substances."
  • Done.
• What are the indexes of refraction for rutile?

Some things that can be added later:

• Should we include electrical conductivity?
• Should we add the natural simulants, such as quartz?
• If we add the natural simulants, should they be sorted chronologically, or in the same order as they appear in the article? (The latter idea is consistent with using special rows as headings.)
• Should there be a separate column for the amount of double refraction? That would allow ranges for the index of refraction of the singly refractive materials. Unfortunately, it might be confusing.

-- Jasper 05:35, 22 Mar 2005 (UTC)

Hi guys, love the table! A couple of thoughts --

• Instead of "state of the art", perhaps it should be "date of introduction", which avoids implicit judgment of which simulant is "best". (And by the way, how did you pick 1476 for diamond? I haven't seen that date anywhere else, except for the first time it was used in a wedding ring, in 1477.)
• Thermal conductivity - we need consistency in the adjectives used. One set is "poor, good, excellent"; another is "low, medium, high, very high"; but no mixing! I'm not sure which is better or whether it matters, but right now Moissanite doesn't fit.
• I'm concerned that the table is going to become unwieldy with many more columns. It's already reached screen width on an 800x600 setup. Not really sure what to do about this, but if you have any ideas.... :)

Other than that, very nice work, and very impressive article! - Bantman 17:55, Mar 22, 2005 (UTC)

The article makes a point of saying when each simulant technology stopped being commonly used. The materials that are still widely used as either diamond jewelry or as diamond simulants (diamond, glass, CZ, and moissanite) have only start dates. (Glass is still used in fracture filling.) The end dates are taken from the article. I chose the term "state of the art" because it implies that while you could still use the material, the material is no longer the leading diamond simulant (especially in terms of amount purchased each year).

The 1476 date is based on Lodewyk van Barquem's introduction of briolette diamonds cut "with absolute symmetry in the disposition of facets". A date of 1450 would also make sense. That is when Agnes Sorel started "the fashion for women to wear diamonds as jewels", "at the Court of Charles VII of France". Source for both dates: Marcel Tolkowsky (1919). Pages 15-20 of the "Historical" chapter of Diamond Design. [1]

In order to keep the table narrow, I tried to use short adjectives. The article states that diamond has "superlative" thermal conductivity. Unfortunately, "super" does not have the same connotations as "superlative", so I used "excellent" instead.

My screen is 800 x 600, so I am trying to keep the table narrow. That is why I have combined the "Index(es) of Refraction" column and the single/double refraction column. It is also why I have used line breaks and abbreviations to keep each column narrow. Thank you for mentioning this issue -- I need to remember that my browser will render the table at a different width than some other browsers, especially if the font sizes are different.

We could also strip out the extra spaces that I added around the ndashes. (I added them because my browser renders the ndash as a question mark.)

-- Jasper 00:53, 23 Mar 2005 (UTC)

Delisted GA

This article has been removed from the Ga list as it has failed WP:WIAGA criteria 2b. Feel free to renominate the article once these issues have been addressed. Tarret 23:42, 23 October 2006 (UTC)

Motive for use should not precede definition

I changed the introduction so that the topic is defined right away, per style guidelines. The reasons people make and buy diamond simulants should come in later; it moved it to the end of the introduction. (The article on Meat analogue doesn't begin "Ethical concerns about the raising and slaughter of animals for meat has lead to..."). Any objections to this can be given here. ± Lenoxus (" *** ") 21:17, 25 February 2013 (UTC)