Photo by MarkNantzPhotography.com.
Designers began using black diamonds in their jewelry around the 1990s, and their popularity increased after a 5-carat black diamond engagement ring was presented to the character Carrie in the 2010 movie “Sex and the City 2.”
Natural single crystal diamonds that appear black are the result of:
1. Black inclusions (the most common type), e.g., graphite, hematite and/or iron
2. Hydrogen-related clouds throughout that are so dense the stone looks black
3. Natural irradiation (“Gems & Gemology,” Winter 2013, Lab notes).
4. A dark-brown color that is so dark, the stone looks black.
Most treated black diamonds are heavily fractured stones that have been heated until the fractures graphitize and turn black. These heated diamonds are often used for beads and melee. They cost about 1/2 to 1/8th the price of a natural single crystal black diamond.
Some treated diamonds that look black have been irradiated. These tend to have a dark green to blue color that is so dark the stone appears black. However, in strong transmitted light, irradiated diamonds usually look dark blue to dark green.
When using transmitted light to discern the actual color, it is typically only viewable at the thinnest point. Even though heated black diamonds can often be separated from irradiated diamonds by their color, distinguishing treated diamonds from natural black diamonds is much more challenging and sometimes requires hi-tech equipment.
Photo by MarkNantzPhotography.com.
Another example of black diamond jewelry by Barbara is in my new book “Diamonds, Their History, Sources, Qualities and Benefits” www.reneenewman.com/diamonds.htm.
Diamond identification info is in my “Diamond Handbook” www.reneenewman.com/handbook.htm and in my “Diamond Ring Buying Guide” www.reneenewman.com/diamond.htm
Guest articles by Renée Newman:
https://gem-spectrum.com/category/renee-newman
About the author:
Renée Newman is a gemologist (GG, GIA), lecturer, writer and author of 15 books on gems and jewelry. Her goal is to provide consumers and jewelry professionals with unbiased, affordable information on how to buy, evaluate and appreciate gems and jewelry. She can be reached through her website:
