Diamond

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal Structure: Cubic, Cleavage: Perfect octahedral, Specific Gravity: 3.52

Formed under extreme high-pressure and high-temperature conditions deep within the Earth's mantle (150-250km deep) over billions of years, transported to surface via volcanic eruptions in kimberlite pipes.

Primary use in high-end jewelry; industrial uses include cutting, drilling, and grinding tools due to its extreme hardness.

Diamonds are the hardest natural substance known on Earth. Many diamonds are between 1 and 3.5 billion years old. The name comes from the Greek word 'adamas', meaning unbreakable.

Identified by light refraction, hardness, and thermal conductivity. Commonly found in South Africa, Russia, Canada, and Australia. Natural diamonds require professional certification to distinguish from cubic zirconia or moissanite.