Diamonds, often associated with glamour and sturdiness, are formed under conditions of extreme pressure and temperature, typically found deep within the Earth's mantle at depths of about 140 to 190 kilometers. These conditions transform carbon atoms into a crystal structure that is well-known for both its hardness and its high refraction of light.
A common myth is that diamonds form from coal. However, this is scientifically inaccurate, primarily due to the different processes and elements involved in the formation of each. Coal is formed from the remains of ancient vegetation, which accumulates in swampy, anoxic environments and, over millions of years, undergoes transformation into peat, lignite, and eventually varieties of coal through increased pressures and temperatures. The presence of other organic compounds and impurities in coal disqualifies it as a candidate for diamond formation.
Diamonds mostly originate from carbon that has been beneath the Earth's crust long before terrestrial plants, the primary source of coal, existed. This carbon, isolated from air and surface processes, crystallizes into diamonds. Another lesser-known source of diamonds is when subducted oceanic plates transport surface carbon deep beneath the Earth's crust, potentially contributing to diamond formation, a process entirely uninvolved with coal deposits.
Additionally, the formation conditions for coal and diamonds differ greatly. While coal forms at relatively low temperatures and pressures near the Earth's surface, diamonds form at high temperatures and pressures incompatible with coal formation conditions. Thus, any notion that diamonds form directly from material like coal is unfounded.
Understanding the origins of such precious mineral forms not only enlightens us about the Earth’s geological processes but also adds to the appreciation of these natural wonders. By debunking common myths such as diamonds forming from coal, we gain a clearer and more accurate picture of the natural world.
