Gem-name guide / Organic / biogenic

Jet

Jet is indexed as an organic or biogenic material in this gem-name directory. The CIBJO nomenclature table associates this name with Jet. Gem names may describe appearance or a material family; a name alone does not identify treatments, origin or quality.

Material or mineral family: Jet
Name classification: Organic / biogenic
Related names / synonyms: Gagat

This entry is not linked to a single mineral species. A gem name can refer to a group, a mixture, natural glass or biological material.

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Names describe materials, not the authenticity, treatment, provenance or quality of a particular specimen. Physical properties vary for mixed materials; values absent from this guide have not been estimated.

Reference snapshot: September 2026. Source dates and uncertainties are retained in the record.