Diamonds are loved and appreciated by just about everyone. For years, white diamonds were the only ones available. But, in more recent years, diamonds of various colors have become more mainstream. Colored diamonds come in various shades that appeal to different people with different tastes. You may be interested in learning what makes a colored diamond gets its color…
Why do Diamonds Come in Various Colors?
First, diamonds are the pure form of the element Carbon. Normally, when colors appear in a diamond, it is the cause of either trace elements or internal distortions that in the crystals as the diamond forms. Although most diamonds appear white, or colorless when they are cut, they are normally yellow when they are mined.
Diamond color is graded on a scale of D to Z, based on the amount of color that is present in the stone. Diamonds that are rated “D”, “E” or “F” are colorless. Those that are “G” through “J” are near colorless, and those that are “K” through “M” have a faint yellow tint to them. Diamonds that get a rating of “N” through “R” are very light yellow and those that are “S” through “Z” are light yellow. However, diamonds can come in virtually every color of the rainbow, and their intensity from “Faint” at the lower end to “Fancy Vivid” at the high end.
Impure “Fancy” Diamonds
Most diamonds are impure or “fancy”. Diamonds in this category have structural defects that are caused by chemical impurities. These impurities affect the color of the diamond and result in a variety of naturally-colored diamonds. The impurities include the amount of nitrogen that is present in the stone, the stone’s exposure to radiation during its creation, and other natural factors.
The intensity and hue of a diamond are major factors in determining the intrinsic value of a diamond. In most cases, a diamond with a yellow hue is considered inferior and is often sold at a discounted price. On the other hand, blue and red diamonds are rare and considered to be valuable.
Red diamonds are the most rare, and therefore the most expensive, colored diamonds. Various shades of red are caused by the electron structure it experiences during its voyage to the surface of the earth.
Purple diamonds are the second-most rare diamonds on earth. The exact cause of purple coloration in a diamond is not known, but there are several theories. Many scientists believe purple diamonds are created because of post-growth plastic deformation, change in electron structure, during a stone’s travel from the earth’s mantle to the surface with the help of magma.Most experienced gemologists can easily tell the difference between natural and treated purple diamonds because natural stones tend to have concentrations of color while treat stones have consistent color throughout the stone.
Orange diamonds are created when the stone is modified by Nitrogen.
Green diamonds are quite rare. Some green diamonds are formed by having trace amounts of Nickel mixed into the Carbon However, the coloration of most green diamonds is due to natural radiation that is found in rocks that are near where the stones were created. The radiation traps electrons and createsgreen surface color. However, when green diamonds are formed this way, the surface color washes away when the stone is polished.
Blue diamonds are a result of Boron that is found in trace amounts in the stone. When Boron is present, the Nitrogen level is low and results in the blue color of the stone. Other blue diamonds that are not related to Boron are formed when Nickel or high concentrations of Hydrogen cause the coloration. Recent studies have shown that boron was likely present in ancient oceans.
Pink diamonds are thought to get their color from the changes in the electron structure of the stone during its journey to the surface of the earth, which is called plastic deformation.
Gray diamonds are created by the presence of trace element of Boron or other elements in the Carbon structure of a stone. A gray diamond can also be a black diamond that is not thoroughly saturated.
Brown diamonds get their color from structural defects in the diamond lattice that absorb light.A brown diamond can also get its color from the presence of Nitrogen.
Black diamonds are not caused by impurities like other colored diamonds are. Instead, they are caused by small amounts of graphite and iron clusters that are trapped in the stone. Black diamonds are unique because they appear opaque while other colored diamonds remain translucent. Black diamonds are high susceptible to fracture, so they are difficult to polish and cut. For this reason, black diamonds are normally reserved for industrial use, as their quality lacks in comparison to other diamonds.
The Chemistry of Colored Diamonds
Although each colored diamond is unique, they all owe their appearance to these fundamental chemical reactions:
– Pink and red diamonds are exposed to intense heat and pressure that cause the crystal lattice to distort and absorb particular bands of green light rays.
– Blue diamonds have Boron as their active ingredient. The Boron bonds with Carbon to absorb red, yellow and green light.
– Green diamonds absorb naturally-occurring radiation within the soil. This process also gives green diamonds reflective properties.
– Yellow and orange diamonds have Nitrogen atoms that assemble themselves so that blue light is absorbed and yellow hues are reflected.
– Purple and violet diamonds occur when the lattice is distorted. Hydrogen likely also plays a role in the coloration.
Diamonds come in as many colors as there are colors that exist. For example, two different pink diamonds can be extremely different shades of pink. The differences in shade are due to the variations of different factors, like the amount of pressure a particular stone is under or radiation levels in the mantle layer. To produce a specific hue, all factors must be present at the right time and in the right amounts.
Treated and Color-Enhanced Diamonds
Colored Diamonds generally have a high cost attached to them. So, gemologists have developed more affordable versions for the average buyer. To do so, they take less desirable diamonds and treating them with irradiation and intense heat. Diamonds that start out as yellowish or brown are transformed into diamonds that are beautifully colored. After the treatment, the diamonds are considered to be permanent, although the color may change when exposed to high heat. Putting diamonds through the High-Pressure High-Temperature (HPHT) treatment enhances their hue. It can turn yellow or brown diamonds into sparkling colorless hues.
Mark’s Diamonds does have a great selection of fancy yellow diamonds and blue diamonds in the showroom. Book your appointment today!