FANCY COLOR DIAMOND
Dazzling brilliance. Captivating color. The planet’s most valued gems are fancy color diamonds.
OVERVIEW
ABOUT FANCY COLOR DIAMOND
Gem diamonds in GIA’s D-to-Z range usually decrease in value as the color becomes more obvious. Just the opposite happens with fancy color diamonds: Their value generally increases with the strength and purity of the color. Large, vivid fancy color diamonds are extremely rare and very valuable. However, many fancy diamond colors are muted rather than pure and strong.
BIRTHSTONES & ANNIVERSARIES
Diamond is the birthstone for April and the gem of the 10th and 60th anniversaries. Fancy color diamond adds a unique twist to your celebration.
1 in 10,000
Only one in 10,000 diamonds has a fancy color.
$71.2 million
In April 2017, the Pink Star diamond,
59.60 carats, became the most expensive
gem ever auctioned.
Hope Diamond
The 45.52-carat Fancy Deep grayish blue Hope Diamond is the world’s most famous gem.
FACTS
Mineral: Diamond
Chemistry: C
Color: All colors
Refractive index: 2.42
Birefringence: None
Specific gravity: 3.52
Mohs Hardness: 10
TREATMENTS
There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.
SYNTHETICS
Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.
IMITATIONS
Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.
WHY WE LOVE THIS GEMSTONE
1
Rarest of the rare
Fancy color diamonds are the rarest of the rare. Each is one of a kind.
2
Red
Red diamonds are so rare that only a handful are known to exist.
3
Boron
Less than one boron atom per million of carbon atoms can give a diamond a blue color.
QUALITY FACTORS
The most valuable hues are pink, blue, and green. Slight color differences can impact value.
COLOR
The most valuable hues are pink, blue, and green. Slight color differences can impact value.
CLARITY
Even diamonds with a low clarity grade are prized by connoisseurs if their color is attractive.
CUT
Fancy shapes like radiant cuts are commonly used to maximize the intensity of the color.
CARAT WEIGHT
In pink, blue, green and orange, even fancy color diamonds below a carat are rare and valuable.
FANCY COLOR DIAMOND QUALITY FACTORS: THE COMPREHENSIVE GUIDE
RESEARCH
Explore sources, gemological research, and the role of gems in history.
Sally Eaton-Magaña, Kgotlaetsho Baatshwana, and Norma-Jean Osi, Gems & Gemology, Fall 2025, Vol. 61, No. 3
Dimitry Krugolets and Paul Johnson, Gems & Gemology, Fall 2025, Vol. 61, No. 3
Isabella Pignatelli, Cristiano Ferraris, and Dominik Schaniel, Gems & Gemology, Fall 2025, Vol. 61, No. 3
Recommended Reading
Collecting and Classifying Coloured Diamonds: an Illustrated Study of the Aurora Collection
Stephen C. Hofer
The Fancy Color Diamond Book: Facts & Secrets of Trading in Rarities
Eden Rachminov
Forever Brilliant: the Aurora Collection of Colored Diamonds
Alan Bronstein and Stephen C. Hofer
