A moissanite diamond is not actually a diamond but a gemstone composed of silicon carbide (SiC). It was originally discovered in 1893 inside a meteorite by the French chemist Henri Moissan, who initially mistook it for a diamond. Due to its rarity in nature, moissanite is now almost exclusively lab-grown. Moissanite resembles a diamond visually but differs in composition and some optical properties. It has a higher refractive index than a diamond, which means it exhibits more "fire" or rainbow flashes when light hits its surface. However, in terms of hardness, moissanite ranks 9.25 on the Mohs scale compared to a diamond's perfect 10. The key differences between moissanite and diamond include:

• Composition: Moissanite is silicon carbide; diamond is pure carbon.
• Origin: Moissanite is lab-grown today; natural diamonds are mined.
• Appearance: Moissanite has more brilliance and fire (color flashes) than diamonds.
• Hardness: Diamonds are harder and more durable.
• Price: Moissanite is much more affordable than diamonds.
• Environmental Impact: Moissanite has a smaller carbon footprint as it is lab-grown without mining.

Moissanite is a popular and ethical alternative to diamonds, especially for jewelry like engagement rings, due to its beauty, durability, and affordability. It is important to note that a trained professional can distinguish moissanite from diamond by its optical properties and how it reflects light. In summary, a moissanite diamond is a lab-created gemstone that looks like a diamond but is made of silicon carbide, offering a cost- effective, environmentally friendly diamond alternative with distinct optical characteristics.