Call Now: 310.821.1453
More than 100 million diamonds are sold in the United States each year, yet most consumers know very
little about the product they are purchasing, and how that product is valued. The 4 Cs represent the four
variables that are used to calculate the quality and value of a diamond. Both rough and cut diamonds are
separated and graded based on these four characteristics.
As a consumer, your first step in shopping for a diamond should be to learn and understand the "4 Cs"
diamond grading system. The more you know about how quality relates to value with diamonds the less
likely it is that you will get ripped off. It is important to learn how to read and understand the details of a GIA
(Gemological Institute of America), AGL, or AGS (American Gem Society) "Diamond Certificate" or Sarin
"Diamond Grading Report" or GIA 'Diamond Dossier®.' You will also want to familiarize yourself with the
Federal Trade Commission (FTC) guidelines on jeweler conduct and consumer awareness. This will help
you immensely when you are comparison shopping for diamonds.
When jewelers judge the quality of a diamond cut, or "make", they often rate "Cut" as the most important
of the "4 Cs." The way a diamond is cut is primarily dependent upon the original shape of the rough stone,
location of the inclusions and flaws to be eliminated, the preservation of the weight, and the popularity of
certain shapes. Don't confuse a diamond's "cut" with it's "shape". Shape refers only to the outward
appearance of the diamond and not how it is faceted.
The Importance of Cut Quality
A diamonds cutting proportions, directly effects the refraction of light. In other words how well a diamond is
cut, has everything to do with the degree of sparkle, scintalation and brillance a diamond shows.
When a diamond has a high quality cut (ideal cut), incident light will enter the stone through the table and
crown, traveling toward the pavilion where it reflects from one side to the other before bouncing back out
of the diamond's table toward the observer's eye (see Fig. 1 below). This phenomenon is referred to as
"light return" which affects a diamond's brightness, brilliance, and dispersion. Any light-leakage caused by
poor symmetry and/or cut proportions (off-make) will adversely affect the quality of light return.
The "Shallow Cut" and "Deep Cut" examples in Fig. 2 show how light that enters through the table of a
Modern Round Brilliant diamond reaches the pavilion facets and then leaks out from the sides or bottom
of the diamond rather than reflecting back to the eye through the table. Less light reflected back to the
eye means less "Brilliance". In the "Ideal Cut" example, most of the light entering through the table is
reflected back towards the observer from the pavilion facets.
GIA's new cut-grading system is based on averages that are rounded-up to predict 'light performance,'
while AGS uses a more exacting combination of proportional facet ratios along with ray-tracing metrics
to calculate light return. The "Ideal" designation is an AGS term that is not found on an GIA report. The
GIA will give a symmetry demerit for what it calls "non-standard brillianteering" which some
manufacturers use to 'improve' on the standardized Tolkowsky-type cuts.
The proportion and symmetry of the cuts as well as the quality of the polish are factors in determining
the overall quality of the cut. A poorly cut diamond with facets cut just a few degrees from the optimal
ratio will result in a stone that lacks gemmy quality because the "brilliance" and "fire" of a diamond
largely depends on the angle of the facets in relation to each other. An Ideal Cut or Premium Cut
"Round Brilliant" diamond has the following basic proportions according to the AGS:
* Table Size: 53% to 60% of the diameter
* Depth: 58% to 63% of diameter
* Crown Angle: 34 to 35 degrees
* Girdle Thickness: medium to slightly thick
* Facets: 58 (57 if the culet is excluded)
* Polish & Symmetry: very good to excellent
Symmetry and Polish
The symmetry of a diamond is related to the overall geometry of the diamond. In other words, how well
is the diamond faceted. An example of poor symmetry, would be poorly shaped facets, facets that do
not meet up at perfect points, Uneven girdle and misshaped tables. Cutting problems which effect
symmetry can occur during the faceting process, when one incorrect facet angle can throw off the
symmetry of the entire stone. The chart below shows several common problems to look for.
Perfectly formed Hearts and Arrows patterns with eight hearts AND eight arrows (above, left) are only
found in diamonds that meet the American Gem Society Laboratories' "0" Ideal Cut specifications.
The IdealScope was invented by Kazumi Okuda in the 1970's, and its later incarnation, the
"FireScope," was invented by Ken Shigetomi and Kazumi Okuda in 1984. The first official H & A
"EightStar" diamond was cut in 1985 by Kioyishi Higuchi for Japanese businessman and FireScope
manufacturer, Takanori Tamura
Carat weight is one of the 4 C's, representing the four variables that are used to calculate the quality
and value of a diamond. Both rough and cut diamonds are separated and graded based on these
four characteristics. As a consumer, your first step in shopping for a diamond should be to learn and
understand the "4 C's" diamond grading system.
A diamond or gemstone's "Carat" designation is a measurement of both the size and weight of the
stone. One "Carat" is a unit of mass that is equal to 0.2 grams (200 milligrams or 3.086 grains) or
0.007 ounce. A carat can also be divided into "points" with one carat being equal to 100 points, and
with each point being 2 milligrams in weight. Therefor, a 1/2 carat diamond would be 50 points, a 3/4
carat diamond is 75 points, and a 2 carat diamond is 200 points.
When a single piece of jewelry has multiple stones, the total mass of all diamonds or gemstones is
referred to as "Total Carat Weight" or "T.C.W."
The word "Carat" is derived from the Greek word keration, or "seed of the carob". In ancient times,
carob seeds were used to counterbalance scales, and as a benchmark weight due to their predictably
Hearts and Arrows Diamonds
A perfectly proportioned ideal cut that is cut to the exacting specifications of a Tolkowsky Cut, Eppler
Cut (European Standard), or a Scan D. N. Cut (Scandinavian Standard) will display a "Hearts and
Arrows" pattern when observed through a IdealScope (arrows only), or a H & A Viewer gemscope
All of the grades of diamond clarity shown in the table below, reflect the appearance of inclusions
within the stone when viewed from above at 10x magnification Higher magnifications and viewing from
other angles are also used during the grading process. In "colorless" diamonds, darker inclusions will
tend to create the most significant drop in clarity grade. In fancy-colored diamonds, light or pale
inclusions may show greater relief, making them more apparent, causing a greater drop in grade.
Diamond Clarity Designations
- FL - "Flawless" no inclusions at 10 x magnification
- IF - "Internally Flawless" no inclusions at 10 x mag. - small blemishes
- VVS-1 - "Very Very Small" inclusions hard to see at 10 x magnification
- VVS-2 - "Very Very Small" inclusions. VVS1 better than VVS2
- VS-1 - "Very Small" inclusions visible at 10 x mag. - not naked eye
- VS-2 - "Very Small" inclusions VS1 is better grade than VS2
- SI-1 - "Small" or "Slight" Inclusions or "Imperfections" may be "eye clean"
- SI-2 - "Small" or "Slight" Inclusions or "Imperfections" visible to naked eye
- SI-3 - Inclusions large and obvious, little or no brilliance
- I-1 to I-3 - Imperfect, with large Inclusions, fractures, and flaws
GIA Grading System
The chart in Fig. 4 explains the GIA grading system for inclusions and imperfections. Considerations in
grading the clarity of a diamond include the type of stone, point size and the location of inclusions.
Inclusions that are near to, or break the surface, may weaken the diamond structurally, therefore
reducing its value significantly. On the other hand, it may be possible to hide certain inclusions behind
the setting of the diamond (depending on where the inclusion is located), thus minimizing any negative
impact of the inclusion.
Most all natural diamonds contain small quantities of nitrogen atoms that displacing the carbon atoms
within the crystal's lattice structure. These nitrogen impurities are evenly dispersed throughout the stone,
absorbing some of the blue spectrum, thereby making the diamond appear yellow. The higher the
amount of nitrogen atoms, the yellower the stone will appear.
In determining the color rating of a diamond, the Gemological Institute of America uses a scale of "D" to
"Z" in which "D" is totally colorless and "Z" is yellow. The color chart in Fig. 1 explains the GIA grading
system for clear (not fancy-colored) stones.
Diamond Color Designations
* D, E, F - colorless (white)
* G, H, I, J - near colorless
* K, L, M - faint yellow or brown
* N, O, P, Q, R - very light yellow or brown
* S, T, U, V, W, X, Y, Z - light yellow or brown
The 4 C's of Diamonds
|Jewelry appraisal, diamond appraisal, diamond appraiser, jewelry appraiser, appraisal diamond, appraiser diamond, free online, antique jewelry
appraisal, online jewelry appraisal, appraisal estate jewelry, Los Angeles jewelry appraiser, diamond appraiser, watch appraiser, diamond appraisal online,
appraisal diamond ring, diamond appraisal service, Los Angeles jewelry appraisal, graduate gemologist Los Angeles, Graduate Gemologist, certified
appraiser, certified jewelry appraiser Los Angeles, Los Angeles certified jewelry appraisers, certified diamond appraiser, American society of appraisers,
national appraisal association jewelry, appraisal services, coin appraisal, free appraisal, appraisal management company, antique appraiser, California
appraiser, Jewelry appraisers in Los Angeles, Jewelry appraisers Los Angeles, Los Angeles jewelry appraisers, Los Angeles jewelry appraiser, appraiser
organization, coin appraiser, appraisal diamond, appraised value, pearl appraisal, appraisal insurance services, appraisal report, appraisal ruby, tanzanite
appraisal, emerald appraisal, Jewelry Appraisers Los Angeles, Jewelry Appraisals Los Angeles. Jewelry appraisers Los Angeles, Jewelry Appraisers, Los
Angeles Jewelry Appraiser. Jewelry Appraisal Los Angeles, Diamond appraisers Los Angeles, Los Angeles diamond appraisers, Certified diamond
appraisers, Jewelry appraisals Santa Monica, Jewelry appraisers Beverly Hills, Jewelry Appraisers in Los Angeles, Jewelry Appraisers Hollywood, Jewelry
Appraisers Sherman Oaks, Jewelry appraisers Los Angeles area, Patrick Davis certified jewelry appraiser serving the Los Angeles area, Patrick Davis
Graduate Gemologist certified Jewelry Appraiser in Los Angeles, Jewelry appraiser Los Angeles (310) 821-1453, Gem Secure, GemSecure, GemSecure
jewelry appraisals, Certified Jewelry Appraiser, Jewelry appraisers serving Los Angeles, Los Angeles area Jewelry Appraisers, Gem Secure Jewelry
Appraisers of Los Angeles, Jewelry appraisers in Los Angeles, Gem Secure Jewelry Appraisals serving the Los Angeles area, Certified Jewelry appraisers
of Los Angeles, Gem Secure Jewelry Appraisers of Los Angeles, Jewelry appraisers in Los Angeles. Appraisers serving the Los Angeles area, Jewelry
appraisers in the Los Angeles area, Jewelry appraisers in Los Angeles, Jewelry Appraisers Los Angeles, Jewelry Appraisals Los Angeles, Jewelry
appraisers, Los Angeles Jewelry Appraisers, Los Angeles Jewelry Appraiser, Jewelry appraisals Santa Monica, Jewelry appraisers Beverly Hills,
Jewelry Appraisers Hollywood, Jewelry Appraisers Sherman Oaks, Jewelry appraisers Los Angeles area, Patrick Davis certified jewelry appraiser serving
the Los Angeles area, Patrick Davis Graduate Gemologist certified Jewelry Appraiser in Los Angeles, Jewelry appraiser Los Angeles area, Jewelry
appraisals in Los Angeles, Los Angeles jewelry appraisal, Jewelry Appraisal Los Angeles, Diamond Appraisers Los Angeles, Diamond Appraisals Los
Angeles, Diamond appraisers, Los Angeles diamond appraisals. Los Angeles diamond appraisers, Diamond Appraisal Los Angeles, Los Angeles diamond
Appraisers, Los Angeles Jewelry Appraiser, Jewelry appraiser Los Angeles, diamond appraisals Santa Monica, diamond appraisers Los Angeles, Diamond
appraiser Beverly Hills, Diamond Appraisers Hollywood, Diamond Appraisers Sherman Oaks, Jewelry appraiser, Jewelry appraisers, Jewelry appraisal,
Jewelry appraisals, appraisers in the Los Angeles area, Patrick Davis certified jewelry appraiser serving the Los Angeles area, Patrick Davis Graduate
Gemologist certified Jewelry Appraiser in the Los Angeles area, NUMBER ONE RATED JEWELRY APPRAISER.
Jewelry Appraiser Los Angeles, Jewelry Appraisers Los Angeles, Jewelry Appraisal Los Angeles, Jewelry Appraisals Los Angeles, Jewelry
Appraiser, Jewelry Appraisers, Jewelry Appraisals, Jewelry Appraiser, Diamond Appraisers, Diamond Appraiser, Diamond Appraiser Los
Angeles, Diamond Appraisers Los Angeles, Diamond Appraisal, Diamond Appraisals, Diamond Appraisal Los Angeles, Diamond Appraisals Los
Appraisal of Diamonds, Gemstones, Watches and Fine Jewelry
Patrick Davis is an independent jewelry
appraiser serving clients in Los Angeles, Hollywood, Santa Monica, Long Beach, Hollywood, Beverly Hills, Malibu, Culver City, San Bernardino, San Fernando Valley and the Inland Empire from his offices in
Los Angeles, California. Mr. Davis has over 15 years of jewelry
appraisal experience. He is a Graduate Gemologist (GG), an Accredited Senior Appraiser
(ASA) and a Master Gemologist Appraiser®.
Independent Jewelry Appraiser - Los Angeles, Culver City, Santa Monica, Hollywood, Beverly Hills, Malibu, Long Beach, Orange County, San Fernando Valley, Inland Empire, Riverside, Jewelry Appraisal, Diamond Appraisal, Diamond appraiser, Diamond appraisals
Certified jewelry appraiser los angeles, jewelry appraisal los angeles, jewelry appraiser los angeles, jewelry appraiser, jewelry appraisal, jewelry appraisers in
los angeles, jewelry appraisals in los angeles, jewelry appraiser, diamond appraiser, diamond appraisers, diamond appraisal, diamond appraisals, diamond
appraisers in los angeles, diamond appraisals in los angeles, diamond appraiser in los angeles, diamond appraisal in los angeles, graduate gemologist,
certified appraisals, while you watch, certified jewelry appraiser, jewelry appraiser santa monica, jewelry appraiser beverly hills, jewelry appraiser long beach,
jewelry appraiser riverside, jewelry appraiser hollywood, jewelry appraiser cuvler city, jewelry appraiser san fernando valley, jewelry appraiser malibu, jewelry
appraiser long beach, jewelry appraiser orange county, jewelry appraiser pasadena, jewelry appraiser san gabriel, jewelry appraiser new port beach, jewelry
appraiser san diego, jewelry appraiser coasta mesa, jewelry appraiser palm springs, jewelry appraiser san bernardino, jewelry appraiser tarzana, jewelry
appraiser simi valley, jewelry appraiser reseda, jewelry appraiser calabasas, jewelry appraiser woodland hills, jewelry appraiser santa barbara, jewelry appraiser
oxnard, jewelry appraiser ocean side, jewelry appraiser huntington beach, jewelry appraiser brentwood, jewelry appraiser burbank, jewelry appraiser eagle
rock, jewelry appraiser west los angeles
Certified diamond appraiser los angeles, diamond appraisal los angeles, jewelry appraiser los angeles, jewelry appraiser, jewelry appraisal, jewelry appraisers in
los angeles, jewelry appraisals in los angeles, jewelry appraiser, diamond appraiser, diamond appraisers, diamond appraisal, diamond appraisals, diamond
appraisers in los angeles, diamond appraisals in los angeles, diamond appraiser in los angeles, diamond appraisal in los angeles, graduate gemologist, certified
appraisals, while you watch, certified diamond appraiser, diamond appraiser santa monica, diamond appraiser beverly hills, diamond appraiser long beach,
diamond appraiser riverside, diamond appraiser hollywood, diamond appraiser cuvler city, diamond appraiser san fernando valley, diamond appraiser malibu,
diamond appraiser long beach, diamond appraiser orange county, diamond appraiser pasadena, diamond appraiser san gabriel, diamond appraiser new port
beach, diamond appraiser san diego, diamond appraiser coasta mesa, diamond appraiser palm springs, diamond appraiser san bernardino, diamond appraiser
tarzana, diamond appraiser simi valley, diamond appraiser reseda, diamond appraiser calabasas, diamond appraiser woodland hills, diamond appraiser santa
barbara, diamond appraiser oxnard, diamond appraiser ocean side, diamond appraiser huntington beach, diamond appraiser brentwood, diamond appraiser
burbank, diamond appraiser eagle rock, diamond appraiser west los angeles
J e w e l r y A p p r a i s a l s