Rough Diamond
Diamond (Native Carbon) · Precious Gemstone
Crystal System
Cubic (Isometric); typical habit is octahedral, dodecahedral, or cubic. This specimen shows distorted octahedral faces with trigonal growth features (trigons).
Mineral Group
Native Elements
Chemical Formula
C
Formation Process
Igneous/Deep Mantle; formed under extreme pressure (>4.5 GPa) and high temperature (900-1300°C) at depths of 140-190 km, later brought to the surface by deep-origin volcanic eruptions.
About This Crystal
A raw, uncut octahedron with a high adamantine to greasy luster. Transparent to translucent with a pale yellowish-white tint. The surface exhibits characteristic triangular growth pits known as trigons and a somewhat rounded, 'frosted' appearance common in alluvial specimens.
Physical Characteristics
Color: Near colorless/Yellowish; Streak: White; Cleavage: Perfect octahedral (4 directions); Fracture: Conchoidal; Specific Gravity: 3.51-3.53; Fluorescence: Often blue under long-wave UV (though varies).
Optical Properties
Refractive Index: 2.417 (Singly refractive); Dispersion: 0.044 (high fire, though limited in rough state); Luster: Adamantine.
Hardness & Durability
Origin Region
Notable sources include Russia, Botswana, Canada, DR Congo, and South Africa. Typically found in Kimberlite or Lamproite pipes, or alluvial deposits.
Hardness & Durability
Mohs Hardness: 10 (hardest known natural material); Toughness: Good (brittle due to perfect cleavage); Stability: Extremely stable to chemicals and heat, though can burn at very high temperatures in oxygen.
Care & Maintenance
Safe to clean with warm soapy water, ultrasonic, or steam cleaners. Store separately from other gemstones to avoid scratching them. Avoid sharp impacts due to cleavage planes.
Rarity & Value
Common to Rare depending on gem quality; Value is determined by the '4 Cs' (Carat, Color, Clarity, Cut-potential). Rough industrial-grade is common; gem-grade is highly valuable. Treatments like HPHT or irradiation are common for color enhancement.
Special Characteristics
Adamantine luster, trigons (triangular growth/dissolution marks), and extreme thermal conductivity. May show 'strain' patterns under polarized light.
Lore & History
Historically symbols of purity, invincibility, and status since ancient India (c. 4th century BC). In metaphysical lore, it is associated with the Crown Chakra, amplification of energy, and eternal love.