Measured on K-feldspar. Sample 42-372-24R-1,5 (No. 1-20) VU51-A2 (04MY272) J = 0.001832 (+/- 0.20%) 200-400 µm ~3 grains per fusion. Sample 42-372-38R-3,0 (No. 21-40) VU51-A6 (04MY274) J = 0.001838 (+/- 0.30%) 200-400 µm ~5 grains per fusion. Sample 42-372-24R-1,5 (No. 41-51) VU51-A3 (05MY107) J = 0.001840 (+/- 0.30%) 120-200 µm ~50 grains per fusion. Sample 42-372-38R-3,0 (No. 52-64) VU51-A6 (A-I) (05MY108) J = 0.001842 (+/- 0.30%) 200-400 µm ~20 grains per fusion, VU51-A7 (J-S) (05MY108) J = 0.001843 (+/- 0.30%) 120-200 µm ~50 grains per fusion