Interview with Ruben Obando [GIA Diamonds Graduate]

I Do:  If you could share one piece of advice with someone looking to buy a diamond, what would it be?

RO:  Beware... two diamonds with the same weight, color and clarity are probably not equal in value.

I Do:  How significant could the difference be?

RO: One could be worth twice as much as the other.

I Do:  Will you please elaborate?

RO:  The value of a diamond should never be judged based on a laboratory certificate alone. Diamonds are far more intriguing and complex.

While the laboratory and certificate details are considerations, they are secondary to the findings of a seasoned expert who only after thorough examination can pass judgement on brilliance and value.

I Do:  Is it true that a heavier diamond may not actually be a larger diamond?

RO:  Yes this is quite common... a 1.00 carat diamond cut with beautiful proportion could have a larger face than a 1.25 carat diamond cut to maximize weight...  This raises the obvious question: 'Why are all diamonds not cut with perfect proportion?'

The explanation is simple: Carat weight is the first priority of most diamond buyers and cutters know this... They respond by leaving unnecessary weight in the crown, girdle and pavillion, producing diamonds that are heavier by weight but not larger where it really matters [face size.]

Regrettably, this reality applies to most diamonds produced today.

I Do:  Do specific depth and table percentages guarantee fine cut and brilliance?

RO: The intrinsic character of each diamond combined with the cut are the most important factors in determining brilliance and value.

Understanding depth and table percentages can be helpful, however the dynamics of the proportion best suited to different shape diamonds is both subjective and complicated.

Very significantly, a recently completed 15 year independent GIA study concludes that round diamonds marketed as 'ideal cut' do not in fact produce maximum brilliance.

The 15 year GIA study concludes that diamonds cut with Tolkowsky 'ideal' proportion rated only moderately bright when compared to diamonds cut with different proportions that rated very bright...
[61% table 42.5 degree pavillion and 26.3 degree crown.]

This milestone GIA finding has validated what the finest South African cutters have recognized for decades... the proportion required to create the perfect combination of  'brilliance and face size.' 

I Do:  So what advice do you have for a person trying to make a choice?

RO:  Work with an experienced professional who has access to finer diamonds and understands the relationship between quality and price. Let the expert narrow the selection down to no more than a few stones... then trust your instincts and make your choice. 

I Do:  What color and clarity grades would you recommend? 

RO:  Diamonds in the near colorless range [G to I] make the best sense to me. However, if money is not an issue by all means select a collection color [D to F]... History shows that these colors increase in value somewhat more rapidly.

As for clarity grades... recognize that diamonds with white inclusions toward the girdle [edge] are more valuable than those with black center inclusions. I would select from VS1 to SI2 clarity and look for delicate inclusions not visible to the naked eye. 

I Do:  Does a GIA or AGS certificate guarantee you have a fine diamond?

RO:  Unfortunately not... Remember diamond laboratories will certify any diamond submitted for grading... from magnificent to dull. Certificates simply record measurements and offer an educated opinion on color and clarity.

I Do:  What is fluorescence and how does it affect value?

RO:  When excited by UV light, fluorescent diamonds [typically] reflect a bluish glow. If this glow is 'very strong' the diamond can appear less brilliant [milky] and is substantially less valuable. However, faint or medium fluorescence has little effect on brilliance or value and can actually improve the color appearance of many stones [colors I and lower in particular.]

I Do:  Can a diamond be less than perfect and still be worth buying?

RO:  Certainly... the decision to buy a larger less perfect stone rather than a smaller finer quality [for the same dollars] is a personal choice. In either case the diamond should have beautiful symmetry and brilliance.*