Hi frea, welcome to CDI! What a great question. 

I'm not the one to definitively answer you, but, as I'm sure you can imagine, completely natural diamonds, just like sapphires, are pricier than the heated stones.  It seems that Mother Nature commands a higher price than Man.    Like anything else, something that is rare often is more costly than something that is easily reproduced – simple supply and demand.  Obviously, irradated diamonds can be made available, whereas natural colored stones are catch as catch can.  Also, I have heard that untreated diamonds are more resistant to abrasion and the HPHT treatment, as I understand it, MAY make diamonds more brittle.

If you like the look of treated stones, pedigree is not important to you, and you don't plan on reselling, go for it.  Your rocks are for YOU to enjoy!  On the other hand, if you want to be assured of better durability and better value down the road, then, most likely, untreated diamonds are the way to go.

Let me flag this for David, I'm sure that he'll have something to add (and, goodness knows, he may want to correct me!).

 

yeah I know, thats crazy isnt it and dangerous!!!

While we're on the topic, here's some interesting info from the Government regarding radiated gems...

http://www.nrc.gov/r...es/1990/in90062.html

oh my GGGGOSH....there's some being imported illegally???

Thank gosh I have a source in Australia for semi gems and aussie sapphires, plus dbl for diamonds when Ive saved enough!! phew

No need to be scared Mikla.  Modern irradiated gems are safe from a health standpoint.  The Nuclear Regulatory Commission regulates pretty much everything to do with the industry.  The fact that there's regulation on it should make you feel safer. 

I'm a big proponent of the nuclear power industry, so I like to calm people's fears whenever possible!

If I remember right, a few years ago there was a warning put out about buying irradiated cats eye chrysoberyl and topaz from some eastern countries.  Apparently they were dangerous.  It always pays to be careful when buying abroad.

Interesting story about the largest irradiated diamond known from Wikipedia, the free encyclopedia

On May 27th, 1971, Christie's auction house in Geneva offered to prospective buyers a cushion-cut, 104.52 carat (20.904 g) fancy golden-yellow diamond which would later come to be known as the Deepdene. This was mined in Premier Mines.

Its clarity was stated as VVS1 (with two very small imperfections near the girdle or midsection of the stone) and its vivid-yellow colour guaranteed to be natural by both the German gemmological institute and the University of Mainz.

However, Dr. Edward Gübelin, the founder of the reputable Gübelin Gem Lab in Lucerne, also of Switzerland, had the opportunity to inspect the diamond before the auction took place. Gübelin had a keen eye and experience with examining gems; he was adept at recognizing an artificially colored diamond. The Deepdene had been irradiated, likely by neutron bombardment. Gübelin warned Christie's and any buyers who would listen, but the sale was allowed to continue with the recommendation that it be examined by another lab.

After being sold to jewellers Van Cleef & Arpels for a reported £190,000, the Deepdene was sent to the Gem Testing Laboratory in London, England. The lab's director, gemmological pioneer Basil Anderson, was given the task of substantiating Gübelin's claims. That he did, using spectral analysis with damning results.

Van Cleef & Arpels promptly returned the unfortunate stone for a refund, leaving it somewhat of an unwanted orphan. Its current whereabouts remain uncertain.

The Deepdene gets its name from the Pennsylvania estate of Mrs. Bok, wife of Cary W. Bok, both the diamond's original owners. At the time, the Deepdene weighed slightly more at 104.88 carats (20.976 g) and was mounted in a diamond clip. Harry Winston bought the diamond from the Boks in 1954 and it eventually found its way to a London firm in 1960 and later to its German owner. Assuming Winston did not have the irradiation treatment done, it could have taken place any time between 1955 (when Winston sold it) to 1971, the year it was offered at auction. In any event, the Deepdene is widely considered to be the largest irradiated diamond in the world.

Mikla, I've never heard that story.  Thanks.

GIAGirl, sorry, I'm more dense than usual this morning.  Do you mean all irradated diamonds look neon or off color?

Yes, I'm waiting patiently for my natural red diamond to appear in my Christmas stocking someday... 

Well, looks like I'm going to be the lone voice here!

I've got both natural and irradiated coloured diamonds.  A good irradiated diamond can be difficult to tell apart from a natural one. 

Obviously there are degrees of good and bad irradiated diamonds!  The ones on Ebay are definitely in the generally "bad" category and are usually very low in clarity.  Some companies that irradiate diamonds will only irradiate an SI1 or above and that definitely makes a difference.

I have irradiated yellows, pinks, blues, red, green, purples.  The yellows and greens are the ones that are the most difficult to detect whether they're irradiated or not by eye alone.  The blues are a bit obvious.  Red - well that stands to reason that they're probably not going to be natural    The purples can be also be confused with naturals.

At the end of the day, they're still diamonds, very pretty and sparkly!  So, I'm afraid I will still buy natural and irradiated!

Puts head down and runs for the hills .................. 

IHADP!   

Happy to oblige ...................  ok some of my yellows ..........  Which ones are natural, which ones irradiated?

1.


2.


3.


Same ring different shot!


4.  (sorry not a good picture)


5.  (ignore the ring as it's the same as number 1 above)


6.


7.


8.


For obvious reasons I haven't included my purchases from DBL!