Diamond Color Characteristics

According to the characteristics of diamond color, diamonds are generally divided into two categories: colorless series and colored series.

The colorless series, also known as the Cape series, includes diamonds from colorless to light yellow, light brown, light gray and other hues. Among them, the most common ones are diamonds with a yellow tint, which is mainly due to the small amount of N element in them. Most of the diamonds produced in nature belong to this series.

The color series includes yellow, golden yellow, brown, red, pink, purple, blue, green and other colors. Most fancy colored diamonds are dark in color and intense to medium saturated fancy colored diamonds are extremely rare. Colored diamonds are caused by a small amount of impurity N, B and H atoms entering the crystal structure of diamonds to form various color centers; or due to the plastic deformation of the crystal when diamonds are formed under high temperature and very high pressure conditions, the internal structure is formed. Dislocations, defects, absorb certain wavelengths of visible light and give diamonds their color. Another situation is that after the formation of diamonds, in the long geological age, due to the radiation of radioactive elements in the surrounding environment, the crystal structure of diamonds will be damaged, which will also cause diamonds to produce color. So, there are many possible reasons for a diamond's color.

(1) Colorless series and yellow diamonds Pure diamonds without structural defects are colorless, but very rare. As an isomorphic substitution element of C, N often exists in the crystal structure of diamonds, making diamonds appear yellow. The higher the content of N element, the deeper the yellow color of diamonds.

(2) Blue diamond A small amount of B element replaces the C in the diamond to make the diamond appear blue. According to data records, blue diamonds without B were discovered in Argyll, Australia, which was caused by the H element.

(3) The color of pink and maroon diamonds is mainly caused by the plastic deformation of diamond crystals.

(4) The color of green diamonds is caused by radiation from radioactive elements.