| Rare Earths | Bernstein (1982) | |
| Adams (1965) | ||
| Reflectance spectra | Gaffey (1986) | |
| Nitsan and Shankland (1976) | ||
| Hunt et al. (1972) | ||
| Hunt et al. (1971a,b) | ||
| Hunt and Salisbury (1971) | ||
| Hunt and Salisbury (1970) | ||
| Rhodocrosite | Mn2+ | Hålenius et al. (2007) |
| Rossman (1988) | ||
| Rhodonite | Mn2+, Mn3+ | Gibbons et al. (1975) |
| Faye (1975) | ||
| Gibbons et al. (1974) | ||
| Mn2+ | Marshall and Runciman (1975) | |
| Lakshman and Reddy (1973c | ||
| Reddy (1973) | ||
| Manning (1970) | ||
| Manning (1968b) | ||
| Riebeckite | Fe | Allen (1976) |
| Manning and Nickel (1970) | ||
| Faye and Nickel (1970) | ||
| Burns (1970a) | ||
| Rockbridgeite | Fe, IVCT | Mattson and Rossman (1987a) |
| Amthauer and Rossman (1984) | ||
| Ruby (see corundum) | ||
| Rutile | Ti IVCT | Khomenko et al. (1998) |
| Khomenko et al. (1996) | ||