Mono-crystalline and glass prisms for the calibration of reflection-photometers.

Strontium-Titanat R about 5,3%
Cubic Zirkonia (C-Z) R about 3,2%
Gadolinium-Gallium-Garnet (GGG) R about 1,7%
N-LASF46A R about 1,3%
Yttrium-Aluminium-Garnet (YAG) R about 0,9%
Sapphire R about 0,6%
Spinel R about 0,4%
Glass-NG1 R = 0%

Reflection at λ = 546 nm and under oil immersion according to ISO/DIS 7404/5