
gemstone
Green tourmaline (likely elbaite)
Tourmaline group; likely elbaite, complex borosilicate such as Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
AI-generated identification · may be incorrectSmall rough green crystal aggregate with vitreous luster and prismatic form; tourmaline hardness is 7–7.5 Mohs, with no distinct cleavage, trigonal crystal symmetry, and specific gravity about 3.0–3.3.
Identified More gemstone →
Explore Green tourmaline (likely elbaite) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Small rough green crystal aggregate with vitreous luster and prismatic form; tourmaline hardness is 7–7.5 Mohs, with no distinct cleavage, trigonal crystal symmetry, and specific gravity about 3.0–3.3.
Formation & geological history
Forms mainly in lithium-rich granitic pegmatites through late-stage hydrothermal crystallization, generally during Precambrian to Phanerozoic magmatic events. The photograph alone cannot establish its geological age or exact species.
Uses & applications
Transparent gem-quality material is faceted for jewelry; opaque or fractured pieces are mainly collector specimens and sometimes used as mineral teaching samples.
Geological facts
Tourmaline is strongly pleochroic and becomes electrically polarized when heated or compressed (the pyroelectric and piezoelectric effects). Green color commonly results from iron, chromium, or vanadium.
Field identification & locations
Look for a glassy, elongated crystal with lengthwise striations, triangular/trigonal cross-section, and strong green color zoning; confirm with hardness, specific gravity, and analytical testing. Common sources include Brazil, Afghanistan, Pakistan, Mozambique, Nigeria, and the United States.
More like this
Other gemstone specimens
Gemstone Ring
N/A - Set piece of jewelry, likely Amethyst or Garnet with Diamond or CZ
gemstone
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
mineral
Topaz
Al2SiO4(F,OH)2
mineral
Amber
Succinite (Organic Gemstone)
mineral
Diamond and Gold Jewelry
Carbon (Diamond) / Au (Gold)
gemstone
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary