Diamond

Hardness: 10 (Mohs scale), Color: Typically colorless, but can be yellow, brown, green, blue, pink, or red due to impurities/defects. Luster: Adamantine. Crystal Structure: Isometric (cubic). Cleavage: Perfect in four directions. Specific Gravity: 3.5-3.53.

Formation Process: Diamonds form under extremely high pressure and temperature conditions (typically 150 km or 90 miles deep within the Earth's mantle) from carbon. They are brought to the Earth's surface by deep-source volcanic eruptions through kimberlite and lamproite pipes. Geological Age: Most natural diamonds are between 1 billion and 3.5 billion years old.

Industry: Cutting, grinding, and drilling tools; specialized windows; heat sinks for electronics. Jewelry: Highly prized as gemstones due to their hardness, high dispersion (fire), and brilliance. Construction: Used in diamond-tipped saws and drills for cutting concrete and asphalt.

The largest rough diamond ever found was the Cullinan Diamond, weighing 3,106.75 carats. Diamonds form deep within the Earth's mantle and are brought to the surface through volcanic eruptions. They are the hardest known natural material.

How to Identify in the Field: Rough diamonds typically occur as euhedral to subhedral crystals, often with octahedral or dodecahedral forms. They have an adamantine luster. Their extreme hardness makes them scratch nearly all other materials. Common Locations: Primarily found in kimberlite pipes in regions such as South Africa, Botswana, Russia, Canada, and Australia; also found in alluvial deposits (riverbeds). Tips for Collectors: Due to their high value and rarity, finding gem-quality diamonds in the field is extremely rare. Identification usually requires specialized geological knowledge and equipment.