| Superficial stones | No. of samples | 226Ra (Bq・kg−1) | 232Th (Bq・kg−1) | 40K (Bq・kg−1) | Country [Ref.] |
| Igneous plutonic | 387 | 78 (0.8 - 588) | 89 (0.3 - 906) | 1049 (24 - 2040) | European Union [17] |
| Igneous volcanic | 86 | 160 (16 - 709) | 163 (8 - 750) | 1295 (170 - 2354) | |
| Metamorphic | 148 | 27 (0.7 - 166) | 21 (0.0 - 142) | 395 (0.2 - 1891) | |
| Granitesa |
| (4.9 - 190) | (4.5 - 450) | (190 - 2029) | Brazil [14] |
| Volcanic tuff stonesa | 76 | (2 - 263) | (8 - 401) | (99 - 2107) | Turkey [25] |
| Granites | 50 | 47 (17 - 85) | 83 (62 - 114) | 1426 (1315 - 1551) | Nigeria [26] |
| Granitoid outcropsb | 7 | 44 (29 - 53) | 56 (51 - 60) | 1133 (711 - 1355) | Italy [9] |
| Granites |
| 67 (2 - 95) | 95 (1 - 450) | 1200 (50 - 3800) | Greece [27] |
| Granites |
| 187 (80 - 330) | 118 (100 - 140) | 852 (250 - 1300) | Egypt [28] |
| Granites | 20 | 659 (46 - 6180) | 598 (92 - 3214) | 1218 (899 - 1987) | Pakistan [29] |
| Ranyah Anomalous raw Granites | 4 | 667 (305 - 1120) | 319 (161 - 491) | 586 (282 - 893) | Saudi Arabia [Present Work] |
| Ranyah Normal raw Granites | 22 | 45 (18 - 77) | 39 (16 - 73) | 1178 (954 - 1531) |