Corundum spectra

Corundum Visible Spectra (generally 350 - 1200 nm)

Corundum occurs in several colored varieties. Ruby is red because of its Cr³⁺ content. Yellow sapphire owes its color to Fe³⁺. Blue sapphire derives its color from the Fe²⁺ - Ti⁴⁺ and the Fe²⁺ - Fe³⁺ intervalance charge transfer. Green sapphires contain a mixture of the blue and green colors.

Images of representative corundums

Ruby GRR 1843; Ruby obtained in Chathaburi, Thailand, 0.787 mm thick, looking down the c-axis. All the features are from Cr³⁺ including the sharp spin-forbidden band near 695 nm. Data files: a, 24K;
Ruby GRR 1843; Ruby obtained in Chathaburi, Thailand, 0.758 mm thick, looking down the c-axis. Spectra as a function of temperature (27, 300 and 600 C). Data files: 27 degrees, 19K;, 300 degrees, 19K;, 600 degrees, 19K;
Ruby GRR 1843 animation; A movie showing the change of color of ruby 1843 as a function of temperature: 0.758 mm thick, looking down the c-axis (795 KB).
Sapphire GRR 1020 (6K); Medium blue sapphire from an unknown locality (probably in Australia) presented normalized to 3.00 mm thick. All the sharp features are from Fe³⁺ and the broad features which dominate the spectrum are from intervalence charge transfer between Fe²⁺ and Ti⁴⁺ and between Fe²⁺ and Fe³⁺. Data files: a, 15K; c, 26K
Sapphire GRR 1798 (6K); Pale blue sapphire from the Missouri River near Helena, Montana, 3.23 mm thick, looking down the c-axis. All the sharp features are from Fe³⁺ and the weak, broad features are from intervalence charge transfer between Fe²⁺, Fe³⁺ and Ti⁴⁺. Data files: a, 0K;
Picture of a zoned sapphire crystal from Laos with clickable spectra in different zones.

Data Files

no other data files

Corundum Infrared Spectra (generally 4000 - 3000 cm^-1)

Data files and images of OH in corundum

to come in the future

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