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Jet is generally classified as a lignite coal and has a high carbon content and a layered structure. It is typically black to dark brown and can sometimes contain tiny inclusions of pyrite. Jet has been carved for ornamental purposes since prehistoric times.

Jet Polished
Jet Classification
Common Name Jet
Species Jet
Jet Optical Properties
Transparency Semitranslucent - Opaque
Dispersion Strength: None
Refractive Index 1.660
Optic Character NA
Polariscope Reaction Singly Refractive (SR)
Fluorescence SWUV: inert
LWUV: inert
Pleochroism None
Jet Characteristic Physical Properties
Hardness 2.5-4
Streak Black-Brown
Specific Gravity 1.190-1.340 Typical:1.320
Toughness Poor
Inclusions In some Jet specimens the original wood structure can be seen.
Luster Vitreous, Waxy
Fracture Conchoidal
Cleavage None
Jet Chemistry & Crystallography
Chemical Name hydrated hydro carbon
Chemical Formula C,H,O-2H2O
Crystal System NA
Chemistry Classification Organic

Jet Colors

  • Black Jet Black
  • Brown Jet Brown

Alternate Names

Whitby Jet

Countries of Origin

United States of America (the); United Kingdom of Great Britain and Northern Ireland (the)

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This page was created on June 27, 2014.

This page was last edited on October 24, 2019.