Question about black diamonds

[Nashville]

I will post this in RT as well, but I've gotten a lot of good advice here, so a few questions.

What are the most common treatments associated with black diamonds? What should I be avoiding? Will any of these treatment affect long term durability of the stone?

Say I want to buy a parcel of black diamonds. Should I be looking for certified stones? Would it be wise to pay for a GIA cert, or is "in house" sufficient (this is what Leibish and Co. is offering on theirs)

I'm finding mostly only rounds, but I think a baguette halo (something like what is shown in the picture, but with and oval and without the double halo and smaller airline) would be really special. How much trouble is it going to be finding black diamond baguettes and if it's impossible, where can I locate rough material for cutting?

I know a lot of lapidaries choose to not work with rough they haven't sourced, so how likely is it I will find someone to source and cut rough black diamond, and will it be ridiculous price wise?

Thanks in advance!

 

[VapidLapid]

It takes special lapidary equipment, different than other gemstones, to cut diamond. There is also grain in the crystal structure that has to be taken into account. A custom cut diamond is a totally different species than a colored stone.

 

[T L]

Black diamonds are typically irradiated to get more even black color throughout. Black spinel is an all natural (non-treated) option.

 

[chrono]

Black diamonds are usually irradiated but I believe the treatment to be stable and permanent. If looking for melees, it doesn’t make any sense to get certification as I think GIA will not create a report for melee sized diamonds. Baguettes are a huge challenge and super expensive because to get the stones to square up correctly, they are usually custom cut to fit. When it comes to cutting diamonds, you’ll most likely have to go to a diamond cutter to get this done as the tools used are probably different.

 

[serenitydiamonds]

For larger black diamonds, if you want an untreated one, you need to get a GIA report on it as there are tons of irradiated stones. Typical treatments involve irradiation, and are easy to spot if you have a trained eye.

I wouldn't recommend cutting it yourself.

--Joshua

 

[LD]

You'll find it difficult to find ones that aren't irradiated - especially if you're looking for accent diamonds. However, irradiated is very common and because black diamonds have a limited market and are not particularly sought after (or expensive when you compare to fancy coloured diamonds), IMVHO I wouldn't spend money getting a GIA report BUT of course it's a matter of opinion. Interestingly, I would always recommend getting reports but in for black diamonds I feel differently! None of the ones I own have reports - and that includes my biggest which is over 4ct.

Joshua - for tuition purposes, I'd love to know how you can spot the difference between irradiated and non irradiated please? I've assumed all of mine are irradiated but one was sold as natural (which I doubt but you never know)!

 

[serenitydiamonds]

Joshua - for tuition purposes, I'd love to know how you can spot the difference between irradiated and non irradiated please? I've assumed all of mine are irradiated but one was sold as natural (which I doubt but you never know)!

It's actually pretty easy to find them untreated if you contact a color stone dealer. Most already mounted stuff is mostly irradiated though.

Suuuure. First tell, color, is it Blackish-Black or Blackish-Brown? Natural ones are a deeeeeep obscured brown, not black. Second tell, under a loupe a natural black diamond will have numerous splotchy or veined inclusions and the material will be translucent to a slight degree. When they are sitting next to each other, the irradiated is very noticeably different in most cases.

Naturally a lab is necessary for 100% confirmation.

--Joshua

 

[LD]

Thank you Joshua. Most informative.

Another question if I may? Am I correct that only some black diamonds will fluoresce (similar to the way that only some white diamonds do)? OR Do they all? The fluorescence in this one is so odd! It doesn't react like a white diamond as you can see and only some bits seem to fluoresce giving it the appearance of an alien!

Nash - apologies for the threadjack and I hope you don't mind but I find this subject fascinating.

 

[serenitydiamonds]

Very interesting. Not sure if they all do, but some will yes. It looks very alien in the photo.

--Joshua

 

[Treenbean]

Just wanted to add my two cents. On deco rings like that usually the sapphires are calibre cut but I think the black is enamel, which is typical of rings in that era.

 

[Gempassion]

You can find some black spinel here:

http://www.aussiesapphire.com.au/in...th=140&zenid=6687e93f18300b345fcd175df3a18db5

 

[Nashville]

This is all fascinating, thanks everyone! Loving those cool pics!

 

[iLander]

These people have a lot of black diamonds, and I think Kenny got his blue diamond there:

http://www.fancydiamonds.net/black_diamonds

 

[movie zombie]

You can find some black spinel here:

http://www.aussiesapphire.com.au/in...th=140&zenid=6687e93f18300b345fcd175df3a18db5

i highly recommend aussiesapphire as i've purchased some black spinel from andrew in the past.

MoZo

 

[Nashville]

I will look into the spinel, thanks!