A Word About Fluorescence

What is Diamond Fluorescence?

Fluorescence is the colour given off from a diamond when it is exposed to UV or Black light. Think of your friend’s teeth and white clothes glowing on the dance floor!!!

When a diamond is exposed to UV light it will give of a blue glow varying in intensity according to the strength of fluorescence the diamond displays.

Only about 25-35% of all diamonds display fluorescence.

Fluorescence does not affect the clarity or brilliance of a diamond though rarely; strong to very strong fluorescence can cause a hazy or milky appearance in diamonds which are at the top end of the colour scale.

What causes Fluorescence?

A diamond is basically crystallized carbon, formed over millions of years under the earths crust. It is the presence of trace minerals such as Boron Aluminium and Nitrogen that cause fluorescence.

It is worth noting at this point that Fluorescence is not a grading factor in diamonds, as are colour cut and clarity! Fluorescence is used more as a distinguishing characteristic of a diamond.

However it can affect the price of a diamond according to its strength and the colour of the diamond displaying fluorescence

Fluorescence strength is graded from
None- Faint - Medium – Strong - Very Strong

diamond fluorescence

Is fluorescence a good thing or a bad thing?

This depends on the colour of the diamond!
Diamond colour is graded from D – Z with D having no discernible colour (i.e. pure white) all the way to Z , displaying a visible yellow tinge.

diamond colour scale

When is fluorescence a bad thing?

Generally the better colour the diamond, the less desirable the presence of fluorescence is, Especially strong to very strong, as stones at the top end of the scale tend not to have enough colour to balance out the fluorescence.
Strong to very strong fluorescence can also cause a diamond to look milky or hazy.

When is fluorescence a good thing?

For diamonds at the lower end of the colour scale say L – K - The blue tinge of the fluorescence can actually be an enhancing factor as the blue fluorescence can balance out the yellow colour to give the stone the appearance of being higher up the colour scale than it actually is ( i.e. look at least a grade whiter!)

Should I worry about buying diamonds that have fluorescence?

A study by the GIA in 1997 found that fluorescence has no discernible effect on the appearance of a diamond. Especially when viewed table up, under normal lighting situations by the average observer I.e. the jewellery buying public. In fact even professional stone graders do not always agree on the effects of fluorescence on differing stones.

So follow your heart! if a certain diamonds sparkles and catches your eye. Go for it!