Dichroism and pleochroism

Different colours shown by a crystal when viewed along different axes in transmitted light: cordierite (iolite) blue and grey, tourmaline, tanzanite three colours (trichroic). Seen with a dichroscope.

Sources

Gemological Institute of America — Gem encyclopedia and glossary
Mindat — Mineralogical glossary (link only)

Cite this article

Stratum Study. "Dichroism and pleochroism" (Glossary). Stratum Study pack 2026.09, as of 2026-09-16. https://stratum.black/study/glossary/dichroism. Accessed 2026-09-20.

BibTeX · CSL-JSON

@misc{stratum-dichroism,
  title        = {Dichroism and pleochroism},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/glossary/dichroism}},
  year         = {2026},
  note         = {Glossary article, Stratum Study pack 2026.09, as of 2026-09-16; sources: stratum. Accessed 2026-09-20.}
}

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