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Appraising fancy colored diamonds


#1

I have a diamond ring in for appraisal with a medium-brown .75 ct
round brilliant diamond, SI2. I don’t get many fancy diamonds like
this for appraisals, and I’m unsure as how to find a value for this
stone. I am also uncertain of the proper way to describe color for
these stones. Is there an “official” color chart or terminology to
use when describing these diamonds on an appraisal (like GIA’s
standard grading chart)?

Thanks

Douglas Zaruba
35 N. Market St.
Frederick, MD 21701
301 695-1107
@Douglas_Zaruba


#2

Douglas, GIA describes all fancy color diamonds as Faint, Very
Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Dark, Fancy
Deep and Fancy Vivid. The Argyle mine (where many brown, red, pink,
purple and purplish pinks are mined) developed a range described as
C1 through C7, with C1 - C6 described as “Champagne” color and C7 as
"Cognac." GIA does not recognize Argyle’s descriptive terms. Just as
with grading colorless diamonds, a skilled grader/appraiser uses a
set of masterstones to compare fancy colors to assign a fancy color
grade. Color grading by eye even with experience is very difficult.

There are two basic ways to find values, the first of which is trade
experience. In other words, the more you deal with them, the more
you learn about what’s going on in the market, and general pricing
knowledge. The other is to subscribe to a pricing guide. Rapaport
Diamond Report, Michelson Gemstone Index, The Diamond Registry and
The Guide are all well-established price guides. And, to be honest,
very few professionals who pay a subscription to these guides would
be willing to post their pricing online. Then again,
price guides aren’t the be-all and end-all of price sources. The
phrase “I’ll give you 20% back-of-Rap” means “I’ll sell you this
diamond (or parcel) at 20% less than the Rapaport Diamond Report
price guide.”

Sometimes, a good way to get prices is to check with your supplier
to see what a stone of similar quality would cost you. However you
go about it, I wish you the best.

James in SoFl


#3

Douglas,

Two books than can help further your education in colored diamonds:
Hofer, S., Collecting and Classifying Coloured Diamonds and my own
humble offering (see link at bottom of page). You will also find
three interesting articles in G&G spread over several years.
However, color evaluation in fancy colored diamonds is very tricky,
if you have no experience you should defer to the experts. Most
reasonably fine colored diamonds, if worth evaluating, are color
graded by GIA. The GIA-GTL grading report is the sine qua non of
color grading. When I am evaluating a colored diamond I insist that
we begin by obtaining a GIA cert.

Price charts do exist, e.g. The Guide, but the rarer the color the
less accurate they become. They are ok for yellows and browns but
close to useless with blues, greens, pinks, reds, oranges.

Richard

Kindly check out our online gallery: www.rwwise.com

For Information and sample chapters from my new book:


#4

James,

I’m very familiar with the “RAP” sheet, but it never gives values
for fancy colors. Since I don’t handle a LOT of these stones, I can
only “guess” as to the value. I’m looking for a way to make that an
"educated guess."

Grading stones for fancy colored diamonds would be nice, though I
suspect that having a set for every color would be VERY expensive. I
have never seen nor heard of sets like this, not for retail shops
anyway. I believe that the GIA terms would be appropriate to use in
an appraisal, and probably the Argyle’s term as well, as long as you
could match the color to the term. Have you seen any charts or photos
that describe these colors? In the absence of grading stones, that
may be the only way to attempt to describe color.

I have to assume that since fancy colored diamonds aren’t commonly
seen by the majority of retailers, and since they are becoming more
popular, this will become a common problem for the appraiser.

Thanks for the info,
Doug

Douglas Zaruba
35 N. Market St.
Frederick, MD 21701
301 695-1107
@Douglas_Zaruba


#5

Hi in the issue of In Store I got yesterday is a Champagne diamond
add with color grades in a photo marked C1 C2 etc it is the first
time I have ever seen this grading in print.

Teri
America’s Only cameo Artist
www.cameoartist.com


#6

Doug,

Although I would not depend on a chart or picture to determine color
of a Gemstone you can get a good idea of the Argyle color chart and
the corresponding grade in The Argyle Diamonds / Rio Tinto
advertisements. I recently say one in the magazine INSTORE.

Argyle also has a website at www.argylecd.com. There may be a color
chart on the website but I have not looked.

As with Colored Gemstones, values for Fancy Colored Diamonds is very
subjective. The rarer the color more subjective the value.

A list of Diamond wholesalers that specialize in Fancies can be
found in the JCK or National Jeweler Directories. This is were I
would start to determine value. You may also look on Polygon if you
have access.

Good Luck
Greg DeMark
email: greg@demarkjewelry.com
Website: www.demarkjewelry.com


#7

Doug,

That gives me a nice new idea for my website. I’ll see if I can find
a dealer who is willing to part from his photographs for educational
purposes.

Alain


#8
    Grading stones for fancy colored diamonds would be nice,
though I suspect that having a set for every color would be VERY
expensive. I have never seen nor heard of sets like this, not for
retail shops anyway. 

The only masterstone sets I’ve seen for sale, even for colorless (D
to Z scale) diamonds, are CZ sets. To my knowledge, the only way to
obtain a set of genuine diamond masterstones for grading any color
is to put the set together yourself and send them off to GIA (or
another reputable gem lab) for certification.

The requirements are: Round Brilliant cut, minimum size .25ct and
all within .10ct of each other. No fluorescence in colors E through
J and no more than Faint to Medium fluorescence in K through Z.
Clarity SI2 or better with no eye-visible inclusions through the
pavilion and no inclusions that affect color or transparency.
Consistent proportions; crowns and pavilions must not be noticeably
shallow or deep, and girdles must be Thin to Thick (cut grading
terms range from Extremely Thin to Extremely Thick). Girdles may be
faceted, polished or bruted, but not heavily bearded, wavy or have
large naturals or extra facets. There must be at least three stones
to a set. Few use more than ten, and a five-stone set is typical.

Requirements for fancy colored diamond masterstone sets are similar.
Looking at the above requirements shows that even a standard set for
colorless diamonds is quite expensive. I don’t know what GIA charges
for certifying a set, but anyone may inquire directly to them.

    I believe that the GIA terms would be appropriate to use in an
appraisal, and probably the Argyle's term as well, as long as you
could match the color to the term. Have you seen any charts or
photos that describe these colors? In the absence of grading
stones, that may be the only way to attempt to describe color. 

Once, I had a flyer with photos of them but I doubt I kept it. As a
GIA alumnus, I usually discard “romantic” color descriptions, but
sometimes keep them around for comparison. I’ll look around and, if
I find it, I’ll contact you off-list if you want it.

Keep in mind that fancy colored masterstones can be any color. In
fact, each stone in the set can be a different color. They are used
to determine the saturation of the hue, not the specific color. If
it is green, blue, yellow, etc. well, that’s the easy part. Whether
the stone is Faint, Vivid, Intense, etc. THAT is the focus of a
colored masterstone set, just as where a colorless stone falls in
the D to Z scale is the focus of the regular set. If an appraiser
isn’t even familiar with this entry-level knowledge, they shouldn’t
be appraising.

Color grading colorless stones is a tricky business for the
untrained. Grading fancy colored diamonds is even more difficult. I
agree with Richard, a GIA cert should be obtained.

James in SoFl


#9

Doctor,

You are correct, no such master set exists if it did it would be
valued in the millions. In fact, part of GIA’s problem is that they
lack a complete set of masters. They do have a set for yellow
diamonds and that is pictured in “Secrets Of The Gem Trade”, p. 63.
Also, see p. 62 for a comparison photograph of a fancy deep blue
next to a fancy vivid blue diamond.

Currently GIA-GTL uses Munsell color chips to fill the gaps between
its comparison stones. This approach creates difficulties because
Munsel chips are opaque and not appropriate to evaluate color in
transparant media such as gems. In addition GIA uses a specific
neutral gray grading enviorment coupled with a 6200 kelvin daylight
lamp.

GIA’s approach to grading is, in my opinion, a bit too theoretical.
For example a barely blue diamond will be graded as blue while a
comparable barely yellow will fall somewhere toward the end of the
GIA colorless scale. Why?, because, according to the Institute, the
color blue is rare and occupies a more compressed (smaller) area of
three dimensional color space. Thus, the written descriptions on the
cert will often leave the observer scratching his or her head
because the description simply does not match the visual appearance
of the stone. The cushion cut red diamond pictured on p. 223 of my
book is actually quite pink yet the certificate calls it “red”. The
institute does not use terms such as pinkish red, why?, because
since pink is a lighter toned red, the term pinkish red is like
"reddish red" and therefore redundant.

Stephen Hofer author of the excellent book “Collecting and
Classifying Fancy Colour Diamonds” is often asked by collectors to
write letters describing certain important fancy color diamonds. He
has written these for my clients. He uses a colorimetor to measure
the body color of the diamond and compares this with the face up
color. His color descriptions frequently disagree with GIA-GTL
reports on the same stone.

These are just a couple of good examples and reasons why an
appraisal of a fancy color diamond should begin with a GIA grading
report.

Caveat buttock,
Richard
Kindly check out our online gallery: www.rwwise.com
For Information and sample chapters from my new book:
www.secretsofthegemtrade.com