GRR 1824 spectrum, 4K; Cherry opal (red variety)
from Opal Mountain, San Bernardino County, California. Plotted as 1.282 mm thick.
The orangish-red color of this material
comes from Fe3+. The absorption bands are similar in position to those
of hematite suggesting that sub-microscopic domains of hematite are the cause of the color.
Data Files: 1.282 mm thick, 16K; 0.537 mm thick, 18K