Moissanite is a rare, synthetic gemstone made of silicon carbide that's often used as a diamond alternative:
Testing
Moissanites will test positive as a diamond on most diamond testers. This is because moissanite and diamond have similar thermal conductivity properties, which most testers measure. However, there are more advanced testers available that can differentiate between the two by analyzing other properties
Moissanite has a higher refractive index than diamonds, which means it sparkles in rainbow colors when light hits it. It's also more brilliant than diamonds and has almost twice as much fire. Moissanite is durable and has a 9.5 rating on the Mohs scale. However, it's softer than diamonds and may be more prone to scratching.
Production
Moissanite is now exclusively grown in laboratories, which reduces its environmental impact compared to naturally mined gems.
Grading
Moissanite is graded on a scale similar to the GIA diamond color grading scale. It comes in three grades: colorless, nearly colorless, and with faint color hues.
Visually perceive a moissanite as similar to a diamond; it has a higher refractive index, producing more rainbow 'fire' than a diamond when light hits the stone's surface. Diamonds are also physically harder than moissanite, which is 9.25 on the Mohs hardness scale compared to a diamond's rating of 10.
