Black Diamond (Carbonado-type)
Diamond (variety: Carbonado) · Precious Gemstone
Crystal System
Cubic (Isometric) crystal system; typically found as polycrystalline aggregates (massive) or microcrystalline clusters in jewelry settings.
Mineral Group
Native Element (Carbon group)
Chemical Formula
C (Elemental Carbon) with trace Nitrogen, Hydrogen, and Boron; often contains inclusions of Magnetite or Hematite.
Formation Process
Most likely formed through high-pressure, high-temperature (HPHT) conditions deep within the Earth's mantle, or potentially via meteoric impact/interstellar origin according to some theories.
About This Crystal
The specimen features numerous small, round-cut opaque black gemstones pavé-set in a metal ring. They exhibit a high metallic-to-adamantine luster, with a surface characterized by light reflecting off the facets. No transparency is visible as the stones are densely packed with inclusions.
Physical Characteristics
Color: Opaque black or dark charcoal; Streak: White (harder than the streak plate); Cleavage: None (in polycrystalline form); Fracture: Uneven to conchoidal; Specific Gravity: 3.1–3.4; Fluorescence: Inert to weak light green or blue under UV.
Optical Properties
Refractive Index: 2.417 (Opaque); Birefringence: None (Singly refractive); Dispersion: High but masked by opacity; Luster: Adamantine. No pleochroism is present due to opacity.
Hardness & Durability
Origin Region
Primarily sourced from alluvial deposits in Central African Republic and Brazil (Bahia).
Hardness & Durability
Mohs Hardness: 10 (hardest known natural substance); Toughness: High (polycrystalline structure makes it more resistant to chipping than single-crystal diamonds); Wearability: Excellent for everyday jewelry.
Care & Maintenance
Clean with warm soapy water and a soft brush; ultrasonic and steam cleaners are generally safe. Store separately from other jewelry to prevent it from scratching softer gemstones.
Rarity & Value
Relatively common in lower qualities used for commercial jewelry; value depends on the uniformity of color and the polish quality. Most commercial black diamonds are irradiated or heat-treated to achieve uniform color.
Special Characteristics
Contains microscopic inclusions (often graphite or sulfide minerals) that make it opaque; exhibits a unique 'peppered' or metallic sheen under direct light.
Lore & History
Historically, black diamonds were often considered cursed in some cultures due to their dark color, but in modern times they symbolize inner strength, authority, and resilience. They are commonly associated with the Root Chakra and used in modern alternative jewelry designs.