Musings about HPHT vs CVD looking forward the most natural… please weigh in if you have thoughts!

[h52]

Before I got my engagement ring I thought HPHT seemed like the no brainer way to go. It seemed like most of the online comments talked about the hazards of brown CVD and dead give away types of inclusions (from a loupe standpoint?).

But since getting the diamond, I feel like I am suspicious of most hphts having blue nuance and blue as a dead giveaway for a lab diamond. (please correct me if I’m wrong here, as I did read about fluorescence in natural diamonds)

I look at the diamond and sometimes think it’s almost -too sparkly- to be a natural diamond thus dead giveaway for non mined diamond. Because of this I asked a jeweler to test the diamond, and it tested “moissonite”. After that experience I found out that hpht diamonds due to boron inclusions can have electrical conductivity. I also found out that CVD is inert and therefore will likely test like a diamond (no electrical conductivity) unlike hpht.

All of this “new news” to me makes me question if hpht is the way to go? Cvd does have brown and yellow tinges, other inclusions to impede brilliance but could you argue it looks more like a mined diamond this way? Looks like it.. tests like it.. vs hpht blue w/a non diamond test.

Essentially I know I’m hung up on lab vs mined but I cannot justify the fiancé switching lab to mined so it’s not a choice. I’m essentially proud to pick lab but contingent on it looking like mined.

Changing the diamond sounds like a lot of work and therefore I post here to gain insight and maybe to change my outlook about hpht to make peace. After all what makes most sense is to keep whatever my fiancé chooses for me because that would be most meaningful.

I picked lab on the premise that it looked and tested as a natural diamond.

When you picked your lab diamond, was it to get the best sparkle you could get? or was it to fit into the mold of the diamond engagement generation? Either which way, which did you pick? Hpht? Or CVD?

 

[DejaWiz]

There are nuances with either growth process, for sure.
There are nuances with earth grown diamonds, depending on which part of the world and mine that they are plucked from.

The most challenging thing (for me, anyway) when searching for and recommending LGDs is the rapid and constant change in the industry while more growers come on line...with varying levels of equipment quality and maintenance/upkeep thereof, plus the processes and chemical concoctions and ratios for doping continually get tinkered with in the never ending quest to obtain the following when growing diamond rough:

1. Grow it perfect
2. Grow it cheaper
3. Grow it faster

Seems that the limitation is only being able to pick two.

In the end, whichever method (along with the wildly varying recipes of 4Cs) looks best to each individual buyer is ultimately the most important thing.

 

[ecf8503]

I have several CVD diamonds - the first one I bought is a G color, but it does have a brown tint to it unfortunately, and does not look like a G. Since then I've purchased through a different vendor, and none of the CVD's since have any tint at all. My CVD I color faces up so white, it makes me wonder if it was misgraded! I have a HPHT on order, through the same vendor, and it does not have a blue nuance in the video that I can see.

I think if you are comfortable with the vendor, and the stone has been thoroughly vetted, you are going to be fine.

 

[h52]

I have several CVD diamonds - the first one I bought is a G color, but it does have a brown tint to it unfortunately, and does not look like a G. Since then I've purchased through a different vendor, and none of the CVD's since have any tint at all. My CVD I color faces up so white, it makes me wonder if it was misgraded! I have a HPHT on order, through the same vendor, and it does not have a blue nuance in the video that I can see.

I think if you are comfortable with the vendor, and the stone has been thoroughly vetted, you are going to be fine.

I would be very interested to see how you feel about the hpht once you get it in person! Hopefully it’s everything you want!

 

[Rockdiamond]

It’s such a complex equation. An HPHT stone can be colorless with no post growth treatment ( important to some buyers)
CVD growers will bring up the fact a diamond tester may test HPHT as not a diamond. Clearly that will bother some people.
As a dealer, I think my responsibility is not to steer buyers one way or the other- rather to thoroughly vet any lab grown stone and accurately describe it to the consumer. There’s great and horrible examples in both CVD and HPHT.
If a client is looking for a lab grown diamond, and has no preference, I will not restrict my search to one or the other. So many other factors are more important imo

 

[Karl_K]

Good material can be made either way as can not so good material. Buying from a dealer who understands the difference and can communicate it to you after actually seeing the diamond adds value.

 

[monipod]

I think two years ago a lot of us had misgivings about the CVD stones coming out of the Diamond Foundry (Vrai) as their stones consistently leaned towards having a brown tint but as @DejaWiz said, the technology keeps improving and I haven't heard any tint issues coming from Vrai purchases lately. You really just need to find a vendor you can trust. There are 'dud' stones that come out of the ground just as much as there are fails coming out of labs. It's the vendor that finds the cream of the crop to pass on to customers.

As for me, I went with a CVD Asscher because I just couldn't find my 'perfect' Asscher amongst the mined stones listed on JA etc. and for the face-up size, the price was hefty. I fell in love with my L color Asscher and because everything else about it was perfect for me, I caved in as much as a higher colour would have been nice. It's a very clean stone with the sort of warmth you'd expect from an L, mined or lab. I'd buy a CVD again no problem.

My studs and tennis bracelets from James Allen are all HPHT stones and they are lovely, sparkly and white stones. At the size they are, you can't tell if there's any nuance to be honest. If you're looking at a 1+ carat HPHT then it's wise to work with a vendor to avoid any strong blue nuance (unless you like the look!).

I personally have no problem with either process. I think CVDs get a bad rap over HPHT unnecessarily.

 

[hab818]

This is such a great thread to read through. As a novice, previously I felt like I should steer clear of CVD because it seems to carry higher risk of "bad qualities"- brown tint, stria... but for whatever reason, my local jeweler keeps finding HPHT stones that fit my measurements criteria (great HCA scores) but they all end up looking blue compared to the mined, equal-color stone. I personally feel the blue makes the diamond look fake.

I've now expanded my search to CVD stones. It's nice to hear that, under the right circumstances, CVD can actually produce equally nice stones and that my fears are unfounded.

 

[John Pollard]

Buying from a dealer who understands the difference and can communicate it to you after actually seeing the diamond adds value.

More important than ever. Between consumer and dealer and between dealer and supplier. Advancing tech continues raising the LGD quality ceiling, but the basement remains fully occupied as new companies seeking quick revenue jump into the space.

As a dealer, I think my responsibility is not to steer buyers one way or the other- rather to thoroughly vet any lab grown stone and accurately describe it to the consumer. There’s great and horrible examples in both CVD and HPHT.

Definitely. This is the healthiest position a diamond professional can take these days. A lot is happening. Stay current, vet everything, provide full education and let each individual decide what resonates.

I personally have no problem with either process. I think CVDs get a bad rap over HPHT unnecessarily.

The fascinating thing about this sector is the accelerating rate of progress. About a decade ago comparing the world's best HPHT grower to the best CVD grower (for me) was like comparing Ford and Honda. Both fine, if either happens to be your speed. Now the top of each class are like BMW and Mercedes.

That comment isn't limited to jewelry. LGD being created with unique physical and electrical properties can withstand extremely high thermal and radiation loads, with a low coefficient for expansion: Type IIa flawless lenses, X-ray, IR and laser windows, diodes, switches, even quantum computing. All of this bodes well for the quality-progress of LGD, produced either way, for jewelry. Staying current is key.

 

[DejaWiz]

I've now expanded my search to CVD stones. It's nice to hear that, under the right circumstances, CVD can actually produce equally nice stones and that my fears are unfounded.

Key word being *can*.
Unfortunately, as @John Pollard mentioned, there are still a ton of growers occupying the dumpsters of the LGD growers realm, with more and more coming on board to make a quick buck with repurposed old CVD equipment and poor maintenance and upkeep of said equipment.
Professional vetting for key negative attributes is a must, or you may end up with having to select from diamonds cut from garbage rough and traded at the 90-97 back level, indicative of the really bad stuff that looks wonderful under those amazing showroom dazzle lights.
This doesn't just apply to CVD...as HPHT can (and does) have its fair share of junk.
Staying vigilant and patient will win.

 

[Diamond Girl 21]

Totally agree with @DejaWiz. When it comes to LGDS I strongly recommend working with a trusted vendor who can vet the diamonds for you. Best of luck with your search.

 

[monipod]

This doesn't just apply to CVD...as HPHT can (and does) have its fair share of junk.

Applies to natural stones too. There are many dodgy vendors selling badly enhanced mined stones or stones that barely make I1. The stuff I see on eBay... (checking out for fun only of course... lol).

 

[DejaWiz]

Applies to natural stones too. There are many dodgy vendors selling badly enhanced mined stones or stones that barely make I1. The stuff I see on eBay... (checking out for fun only of course... lol).

True words!

If you're ever bored and want a good laugh, search for green lab diamonds on eBay.
I've seen neighborhood department store rhinestones that have better cut quality.

 

[Garry H (Cut Nut)]

I can't decide between diesel, gasoline, hybrid or EV.
But wait!
It comes down to the quality and there are excellent choices in all (both).
In my vehicle example diesel is the choice for towing in the outback of Australia.
Hybrid would my choice for around town and short weekend trips, but my gasoline porsche is more fun, has a nice note, and people tell me better to have that parked in the store driveway. Plus it is sapphire blue.

I think what folk here said is pure wisdom and what matters.

 

[Miss Elle B]

It’s such a complex equation. An HPHT stone can be colorless with no post growth treatment ( important to some buyers)
CVD growers will bring up the fact a diamond tester may test HPHT as not a diamond. Clearly that will bother some people.
As a dealer, I think my responsibility is not to steer buyers one way or the other- rather to thoroughly vet any lab grown stone and accurately describe it to the consumer. There’s great and horrible examples in both CVD and HPHT.
If a client is looking for a lab grown diamond, and has no preference, I will not restrict my search to one or the other. So many other factors are more important imo

Hi David-

I see you’re in the business of LGD’s. As a professional can you make a recommendation on the best diamond tester for HPHT stones?

Any feedback is greatly appreciated!

Thanks,
LaBeth

 

[John Pollard]

Hi David-

I see you’re in the business of LGD’s. As a professional can you make a recommendation on the best diamond tester for HPHT stones?

Any feedback is greatly appreciated!

Thanks,
LaBeth

If your goal is lab grown diamond detection, one stone at a time, the Presidium Ari is reliable. It has a screen display to indicate whether it's conclusion is Moissanite, Diamond or "CVD/HPHT/Type IIa" It does not separate CVD grown stones from HPHT grown stones.

ARI by Presidium

ARI by Presidium is a handheld diamond and moissanite screener that distinguishes colorless diamonds from CVD/HPHT lab-grown diamonds or moissanites—for loose and mounted stones Adaptor not included.

www.presidium.com.sg

For testing many items at once, Yehuda's Sherlock Holmes version 2.0 is reliable and pre-orders are being taken for Sherlock Holmes 3.0. This detector doesn't have a display screen and requires the user to make some analysis of color resulting from exposure to UV. In some cases you can determine what is CVD, but many CVD & HPHT grown stones give the same color result.

Clarity Enhanced Diamonds Inventor | Wholesale Loose Diamonds by Yehuda Diamond Company | Yehuda.com

Yehuda Diamond Company provides clarity enhanced diamonds including princess cut diamonds priced up to 30 percent below wholesale. Certified diamonds at internet prices with local jeweler service to give you the best of both worlds.

m.yehuda.com

For the sake of thoroughness I'll include the normal disclaimers here: Informal detection is not a substitute for gemological laboratory analysis. Inaccurate results may be caused by new technologies by which lab grown diamonds become created, irregular features in natural or lab grown diamonds or other errors.

@Rockdiamond works in the district and may have comments of other recommendations.

Hope it's helpful.

 

[Miss Elle B]

If your goal is lab grown diamond detection, one stone at a time, the Presidium Ari is reliable. It has a screen display to indicate whether it's conclusion is Moissanite, Diamond or "CVD/HPHT/Type IIa" It does not separate CVD grown stones from HPHT grown stones.

ARI by Presidium

ARI by Presidium is a handheld diamond and moissanite screener that distinguishes colorless diamonds from CVD/HPHT lab-grown diamonds or moissanites—for loose and mounted stones Adaptor not included.

www.presidium.com.sg

For testing many items at once, Yehuda's Sherlock Holmes version 2.0 is reliable and pre-orders are being taken for Sherlock Holmes 3.0. This detector doesn't have a display screen and requires the user to make some analysis of color resulting from exposure to UV. In some cases you can determine what is CVD, but many CVD & HPHT grown stones give the same color result.

Clarity Enhanced Diamonds Inventor | Wholesale Loose Diamonds by Yehuda Diamond Company | Yehuda.com

Yehuda Diamond Company provides clarity enhanced diamonds including princess cut diamonds priced up to 30 percent below wholesale. Certified diamonds at internet prices with local jeweler service to give you the best of both worlds.

m.yehuda.com

For the sake of thoroughness I'll include the normal disclaimers here: Informal detection is not a substitute for gemological laboratory analysis. Inaccurate results may be caused by new technologies by which lab grown diamonds become created, irregular features in natural or lab grown diamonds or other errors.

@Rockdiamond works in the district and may have comments of other recommendations.

Hope it's helpful.

Thanks John!!

I appreciate you taking the time to post all the advice and the links. I‘m just looking to do one stone at a time, so the Presidium Ari should be perfect.

Thanks again!
LaBeth

 

[Garry H (Cut Nut)]

Simplest test for a parcel of stones.
Strong magnet and some diamonds will have metalic catalyst.
If about a quarter to a third of stones flouresce likely natural as all synthetic diamond do not.

 

[h52]

As I was reading more about lab diamonds, I came across a categorization scheme like type IIa, type IIb, etc

from what I understand type I is most common with its nitrogen
but type II has no nitrogen, IIa being no anything and IIb with boron.

I wonder... does that mean a lab IIa will in theory test exactly like a diamond and rule out completely any blue nuance.

would there eventually be a niche expensive marketing plan for either natural or lab grown IIa as these would be considered cream of the crop?

As some one who has no sentimental affiliation to the term “earth mined” I wonder if there would ever be a shift from comparing origins, to an elitism focused on purity.

regardless, I have come to realize working with a vendor who can work as your advocate really does make a difference, and to peace of mind too!

 

[DejaWiz]

As I was reading more about lab diamonds, I came across a categorization scheme like type IIa, type IIb, etc

from what I understand type I is most common with its nitrogen
but type II has no nitrogen, IIa being no anything and IIb with boron.

I wonder... does that mean a lab IIa will in theory test exactly like a diamond and rule out completely any blue nuance.

would there eventually be a niche expensive marketing plan for either natural or lab grown IIa as these would be considered cream of the crop?

As some one who has no sentimental affiliation to the term “earth mined” I wonder if there would ever be a shift from comparing origins, to an elitism focused on purity.

regardless, I have come to realize working with a vendor who can work as your advocate really does make a difference, and to peace of mind too!

Your understanding of the different diamond types/subtypes is correct: Most LGDs are Type IIa, with Type IIb being "blue nuance" with some trace of boron mixed into the crystalline matrix. Although it is possible to make a Type IIb with the CVD method, I don't believe any CVD growers of jewelry quality LGDs are making them, so any Type IIb LGDs encountered are made with the HPHT process. Most CVD diamonds (perhaps all of them) are Type IIa. This is all from my understanding of the different LGD growth processes, but IANAE.

For me, LGD purity can be looked at in two different ways:
1. Type IIa for the purest molecular composition.
2. HPHT, for replicating the conditions that the earth makes diamonds.
Put them together (Type IIa HPHT) and I would consider that to be the perfect synthesis of diamond.

 

[Garry H (Cut Nut)]

Your understanding of the different diamond types/subtypes is correct: Most LGDs are Type IIa, with Type IIb being "blue nuance" with some trace of boron mixed into the crystalline matrix. Although it is possible to make a Type IIb with the CVD method, I don't believe any CVD growers of jewelry quality LGDs are making them, so any Type IIb LGDs encountered are made with the HPHT process. Most CVD diamonds (perhaps all of them) are Type IIa. This is all from my understanding of the different LGD growth processes, but IANAE.

For me, LGD purity can be looked at in two different ways:
1. Type IIa for the purest molecular composition.
2. HPHT, for replicating the conditions that the earth makes diamonds.
Put them together (Type IIa HPHT) and I would consider that to be the perfect synthesis of diamond.

The point being?

 

[DejaWiz]

The point being?

Did I misstate something? I'm as eager to learn as I am to share.

 

[Garry H (Cut Nut)]

Did I misstate something? I'm as eager to learn as I am to share.

Most LGDs are Type IIa, with Type IIb being "blue nuance" with some trace of boron mixed into the crystalline matrix.
I never heard anyone claim Blue LGD are type II boron - if so they are electircally conductive - i will ask around.

Although it is possible to make a Type IIb with the CVD method, I don't believe any CVD growers of jewelry quality LGDs are making them, so any Type IIb LGDs encountered are made with the HPHT process. Most CVD diamonds (perhaps all of them) are Type IIa. There are some very rare type I's but I do not believe they are used in jewelry and if they are then my memory thinks they are yellow so would always come with a lab cert (unless small and they probably cost more than small natural).

For me, LGD purity can be looked at in two different ways:
1. Type IIa for the purest molecular composition.
There is hype that type IIa natural have better transparency and color - I have never heard any real studies or evidence of that and many are actually brownish.
2. HPHT, for replicating the conditions that the earth makes diamonds.
Put them together (Type IIa HPHT) and I would consider that to be the perfect synthesis of diamond. the point being?

 

[Garry H (Cut Nut)]

As I was reading more about lab diamonds, I came across a categorization scheme like type IIa, type IIb, etc

from what I understand type I is most common with its nitrogen
but type II has no nitrogen, IIa being no anything and IIb with boron.

I wonder... does that mean a lab IIa will in theory test exactly like a diamond and rule out completely any blue nuance.

would there eventually be a niche expensive marketing plan for either natural or lab grown IIa as these would be considered cream of the crop?

As some one who has no sentimental affiliation to the term “earth mined” I wonder if there would ever be a shift from comparing origins, to an elitism focused on purity.

regardless, I have come to realize working with a vendor who can work as your advocate really does make a difference, and to peace of mind too!

would there eventually be a niche expensive marketing plan for either natural or lab grown IIa as these would be considered cream of the crop? See my comment to DJ just posted.

As some one who has no sentimental affiliation to the term “earth mined” I wonder if there would ever be a shift from comparing origins, to an elitism focused on purity. We have had elitism regarding clarity for centuries. I have always been a fluorescence elitist and sadly no one has worked out how to make visible and near visible UV fluorescent LGD's or HPHT diamonds yet.
But it is a sure fire way to screen out LGD's from natural diamonds.

 

[DejaWiz]

I never heard anyone claim Blue LGD are type II boron - if so they are electircally conductive - i will ask around.


Put them together (Type IIa HPHT) and I would consider that to be the perfect synthesis of diamond. the point being?

I not talking about blue LGD (as in graded on the fancy color scale), I'm speaking towards standard color scale LG diamonds that are tinted light blue because of the presence of boron. I feel that this is the focus of this thread, since fancy blue wasn't mentioned, unless I missed it somewhere.

Point being: nothing, because it was me conveying a personal opinion (...*I* would consider that to be...)

 

[Karl_K]

For me, LGD purity can be looked at in two different ways:
1. Type IIa for the purest molecular composition.
2. HPHT, for replicating the conditions that the earth makes diamonds.
Put them together (Type IIa HPHT) and I would consider that to be the perfect synthesis of diamond.

Long term in my opinion HPHT is dead other than as in some cases an after treatment.
It takes to much energy and is to slow and there are limited avenues to speed it up, CVD on the other hand is in the very early days and is a tech play on tech time.
Apple wants a diamond lens for each camera on its phones.
That is going to drive CVD diamond technology far faster than the jewellery industry ever could on its own.

 

[DejaWiz]

Long term in my opinion HPHT is dead other than as in some cases an after treatment.
It takes to much energy and is to slow and there are limited avenues to speed it up, CVD on the other hand is in the very early days and is a tech play on tech time.
Apple wants a diamond lens for each camera on its phones.
That is going to drive CVD diamond technology far faster than the jewellery industry ever could on its own.

And that's not mentioning the extremely steep price of the HPHT equipment and the upkeep costs.

 

[Garry H (Cut Nut)]

Long term in my opinion HPHT is dead other than as in some cases an after treatment.
It takes to much energy and is to slow and there are limited avenues to speed it up, CVD on the other hand is in the very early days and is a tech play on tech time.
Apple wants a diamond lens for each camera on its phones.
That is going to drive CVD diamond technology far faster than the jewellery industry ever could on its own.

HPHT is likely to remain the main source of LGD smaller diamonds.
They can make squillions in one run vs the long set up time for CVD to polish all the seed crystals and set everything up.
It is why I keep banging on that making dozens of 6mm thick slabs costs less than half of 3mm slabs. That is why 5ct CVD will eventually cost less per carat than 5 one carat or 10 half carat.

 

[Karl_K]

And that's not mentioning the extremely steep price of the HPHT equipment and the upkeep costs.

When you add in the automation costs it will take to scale to that level its not as investment advantaged as you would think.
Humans bring in to much contamination to scale to that level by using hundreds maybe thousands of workers vs automation

 

[Ibrakeforpossums]

For me, LGD purity can be looked at in two different ways:
1. Type IIa for the purest molecular composition.
There is hype that type IIa natural have better transparency and color - I have never heard any real studies or evidence of that and many are actually brownish.

Forgive me for diverting this but I though Type 11a were the purest, as in Golconda diamonds. "Limpid." "Of the first water." They're not?