Benitoite Visible Spectra (350 - 1100 nm)

Benitoite is a rare, strongly dichroic, blue mineral used as a gemstone. It is found in significant quantities only near the head waters of the San Benito River, San Benito County, California. In spite of much effort to study benitoite, the origin of color in benitoite has not been definitively established. Because traces of Fe are found in benitoite, ideas proposed include the Fe²⁺ - Ti⁴⁺ or the Fe²⁺ - Fe³⁺ intervalance charge transfer. While most benitoite is colorless when viewed down the c-axis, there is a very small number (3) of exceedingly rare stones (now cut into gemstones) which are pink in this direction. 

• Images of representative benoite spectra

• blue benitoite spectrum; San Benito County, California. 0.997 mm thick. Or view the expanded visible region; in a slightly less colored zone. Data Files: a, 70K; c, 69K;

• Images of the spectra of unusual benitoite varieties
  

• GRR 303 pink benitoite spectrum; San Benito County, California. It is now a 4.34 mm diameter round faceted stone which appears pink when viewed down the c-axis and blue when viewed perpendicular to the c- axis. The pink color appears in the E||a spectrum.
• GRR 456 pink benitoite spectrum; San Benito County, California. This is the spectrum (in the E||a direction) of the stone with the deepest pink color in existence. It is now a 4.32 mm diameter round faceted stone.
• GRR 1846 orange benitoite spectrum; This is a new color variety of benitoite. The spectrum is presented for a 2.34 mm thick slab.

• Data Files

• no other data files

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