Although a natural piece of carbonado, or black diamond, looks unremarkable, its presumed extraterrestrial origin makes it an object of curiosity and distinction. This mineral's extraordinary beginnings could cause it to become a coveted keepsake in its raw, untreated form, despite the holes and indentations on its permeable surface.
In 1840, the Portuguese discovered black diamonds in Brazil and named them "carbonado." According to a study conducted by geology professor Stephen Haggerty of the Florida International University in Miami, carbon and cosmic dust that came from the extreme heat and pressure of exploding stars billions of years ago produced black diamonds. The diamonds might have been the size of asteroids, each measuring nearly one half mile in diameter.
Black diamonds exist primarily in two places on earth, Brazil and the Central African Republic between Sudan and Chad; they lie along stream beds in these countries. Black diamonds became particular objects of curiosity and interest after scientists theorized that they originated in space from the debris of a "supernova" or exploding star event.
A piece of a black diamond could be round or asymmetrical and contains clusters of crystals. It possesses a porous texture and could appear cloudy to black because of its natural inclusions and the graphite and iron content in the stone. Although a black diamond might resemble ordinary charcoal, the mineral shares the distinction of regular diamonds; both types of diamonds rate a 10 on the Mohs hardness scale, a system that measures the durability of minerals and gemstones.
Natural Black Diamond
The types of black diamonds include the natural black diamond, which appears in assorted size fragments. This stone is used in jewelry; however, its many inclusions cause it to fracture easily, and its natural durability makes it difficult to cut and polish. Because of the black diamond's extreme hardness, the mineral is often used in industrial settings to cut or bore through other objects.
Treated Black Diamonds
Most black diamonds in jewelry have been treated to enhance the stone's natural appearance. Natural black diamonds can be irradiated through a process called neutron bombardment to produce a dark green to black appearance. Another option uses a process called high pressure heat treatment, which simulates conditions deep within the earth's surface, providing a safer treatment alternative than irradiation. In either method, the diamond undergoes a process to bring about uniform color. Enhanced black diamonds can be used with other types of stones to create impressive jewelry.