Moissanite is a unique mineral composed of silicon carbide (SiC), a compound that is exceptionally rare in its natural, crystalline form. Despite being fundamentally different from diamond (pure carbon), moissanite was initially mistaken for diamond due to its extraordinary fire and brilliance. Its high refractive index, which exceeds that of diamond, causes it to reflect light with intense sparkle. The natural occurrence of moissanite is so scarce that virtually all of the material used in modern jewelry and industrial applications is created in controlled laboratory environments.
The Historic Discovery and Meteoritic Origin
The first documented finding of natural moissanite occurred in 1893, far removed from Earth’s crust. The French chemist Henri Moissan discovered minute, shimmering crystals while examining rock samples from a massive impact site in Arizona, now known as Meteor Crater. These particles were embedded within fragments of the Canyon Diablo meteorite, a relic of an asteroid collision. Moissan initially misidentified the crystals as diamonds due to their hardness and optical properties, only correctly determining the mineral was silicon carbide in 1904. This extraterrestrial source explains the mineral’s profound rarity on Earth, as its formation requires specific, high-temperature, carbon-rich conditions associated with cosmic events.
Trace Terrestrial Findings
While the initial discovery was meteoritic, trace amounts of moissanite have been found in specific locations within the Earth’s crust. These terrestrial occurrences are microscopic and hold no commercial value, but they offer insight into the deep-earth conditions necessary for its formation. The mineral is found as inclusions within diamonds or in deep-sourced igneous rocks originating from the mantle, such as xenoliths and kimberlite pipes. The presence of moissanite in these environments suggests that it forms under ultrahigh-pressure conditions in the upper mantle or transition zone. Its existence is also linked to an extremely low-oxygen environment, confirming that moissanite forms naturally on Earth only in fleeting or trace amounts.
The Commercial Source: Laboratory Synthesis
The vast majority of moissanite available today for jewelry and industrial use is produced in laboratories, making it commercially viable. This synthetic creation is the practical answer to where moissanite is currently “found” for the consumer. Scientists effectively replicate the high-energy, high-purity conditions of its natural formation in a controlled environment.
The Lely Process
The most common technique used for growing gem-quality moissanite is a modified version of the Lely process, a seeded sublimation method. This process involves heating silicon carbide powder to extremely high temperatures (often exceeding 2,500 degrees Celsius) within a specialized graphite crucible. The intense heat causes the silicon carbide to sublime, turning directly into a vapor without passing through a liquid state. This vapor then deposits onto a small seed crystal in a cooler section of the chamber, allowing a large, flawless single crystal to grow over several weeks or months. The controlled atmosphere and precise temperature gradients allow manufacturers to create crystals of superior size and clarity, which are essentially non-existent in nature, yet chemically and physically identical to the natural mineral (SiC), differing only in origin.