Colored Diamond Origins | The Diamond Ring Review

Colored Diamond: Sources and Causes of Color Origins


Natural Fancy Colored Diamonds: Sources and Causes of Color
Diamond Color	Sources	Causes of Diamond Color
Red Diamond	Australia, Brazil, South Africa	Irregularities in the crystal’s atomic structure as a result of deformation
Violet Diamond	South Africa, Australia	Hydrogen impurities
Purple Diamond	Russia (main source), South Africa, Democratic Rep. of Congo	Irregularities in the crystal’s atomic structure as a result of deformation
Green Diamond	Borneo, Brazil, Central African Republic, South Africa	Natural radiation; hydrogen, green fluorescence may occasionally make a diamond appear greenish
Blue Diamond	South Africa (main source), Borneo, Brazil, Central African Republic, India (historic)	Boron impurities, sometimes radiation
Orange Diamond	Democratic Republic of Congo, Botswana, South Africa	Probably chemical impurities and structural distortion
Pink Diamond	Australia (main source), Angola, Borneo, China, South Africa, Tanzania, India (historic)	Structural defects combined with various impurities of nitrogen or hydrogen
Yellow Diamond	Angola, Borneo, Brazil, Central African Republic, Guinea, Ivory Coast, Russia, Sierra Leone, South Africa, Venezuela	Isolated nitrogen atoms that randomly take the place of individual carbon atoms or aggregates (clusters) of 3 nitrogen atoms
Green-Yellow Diamond	Brazil, Ivory Coast, Venezuela	Natural radiation, hydrogen, nitrogen
Olive Diamond*	Central African Republic, Sierra Leone, Borneo, Russia	Natural radiation, hydrogen, nitrogen
Black Diamond	Central African Republic, South Africa	Black inclusions
Brown Diamond	Australia, Angola, Borneo, Brazil, Democratic Republic of Congo, Ivory Coast, Russia, Venezuela, South Africa	A defect in the atomic structure of the crystal probably caused by tremendous pressure and evidenced by colored graining
Gray Diamond	Central Africa, Congo	Hydrogen impurities
Chameleon Diamond**	Central Africa	Natural radiation, hydrogen and nickel impurities. Cause of color change not certain. Nitrogen, nickel and/or hydrogen may be involved.

Sources: Gems & Gemology in Review: Colored Diamonds, edited by John M. King, “Nature of Color in Diamonds “by Emmanuel Fritsch in Nature of Diamonds edited by George Harlow,
Collecting and Classifying Colored Diamonds by Stephen C. Hofer, and ncdia.com.
*Olive: a common color term for grayish yellowish green or grayish greenish yellow used by some dealers but not the GIA
** Chameleon diamonds show a color change typically from olive green to brownish yellow when heated to 150 C or when stored in darkness for a few days, but the reverse change is possible.