If you are reading on from my first blog post on a “Diamond Dealer’s Guide” then fantastic, I haven’t lost you with that ramble about the Rap list!
I do try and keep things as un-technical as possible when I write these, because I want it to make sense to everyone, but unfortunately some aspects of the trade are just complicated. And on that note let’s see if I can tackle diamond fluorescence without making you fall asleep (unless you have insomnia… in which case if this helps you sleep, excellent!)
The gemmological definition of fluorescence is the “the emission of cold, non-incandescent light, by a substance when excited by a higher energy source and, therefore, a shorter wavelength”. So far seriously failing at making this accessible…
So in human language, when you shine something like a UV light on a gemstone it may turn a pretty colour. As a gemmologist I think this is just awesome, who doesn’t want to see their opal glow green or their diamond go bright blue? Well: diamond dealers.
Diamonds have some of the most fantastic fluorescent reactions out of all the precious stones, flashing colours from pink, to violet to blue. If you don’t believe me then go to the Natural History Museum in London and have a look at the diamonds in the diamond vault that are under fluorescence!
However, diamond fluoresce is seen by most as incredibly undesirable and we will often be left with fluorescent stones in stock as dealer’s push them aside. I am not entirely sure where the prejudice towards diamond fluorescence comes from, however I do have some theories…
Firstly, it is possible that people are merely looking for another category that can differentiate a ‘good’ stone from a ‘bad’ stone. This theory is definitely true to a degree, however I don’t believe this would have such a profound effect on the trade.
Secondly, it could be argued that fluorescent diamonds have less worth because of gemmological reasons. Some diamonds fluoresce so much that even in very weak UV, such as sunlight, they are glowing a little blue. I am not talking bright sky blue here, but a blue that is so faint you will likely never even notice. However, it is blue enough to cancel out the yellow tones in your stone, therefore your diamond may look whiter then it actually is when viewed in sunlight!
Now, I see this as an overriding benefit; my diamond looks whiter than the colour it was graded at, so therefore looks like a more expensive stone! Sign me up! However, this does mean that if you go to a UV party or a murder scene where they are scanning for blood, then your ring is going to light up like an alien space ship; but unless you find yourself in these situations on a regular basis I am pretty sure you will never have any idea that your little ring could turn into a disco ball… therefore you are buying a diamond that looks whiter than it is and is priced cheaper than others, so who is really going to be laughing at the UV party?
The last argument for the prejudice of diamond fluorescence is that diamonds that fluoresce are always cloudy. This one really came as a shock to me as it isn’t something I had ever heard until a few months ago when I entered into the diamond trade, however it is probably the ‘issue’ with fluorescent diamonds that I hear most in the trade. Here, unlike with the gemmological argument, I don’t need to argue my point: this is simply not true.
Of course you find some fluorescent diamonds that look incredibly cloudy, and I am not saying that all fluorescent stones are crystal clear; however you will just as frequently find a cloudy fluorescent diamond, as you will a cloudy stone with no fluorescence. The properties that cause fluorescence are on an atomic level and, thus, cannot be seen (even with a microscope) and therefore fluorescence does not affect the clarity of your stone.
So, when you’re next on your diamond hunt… maybe have a little looksee at a fluorescent stone; it may be a pleasant surprise!