The prayer niche takes various forms in different kinds of rugs, seldom more than one class having the same form. As a rule that of the Persians is formed by curved lines, while all others are formed by straight lines, those of both the Persian and Turkish classes being pointed, while those of the Caucasian and Turkoman classes may either be pointed or flat at the top, usually the latter.
In differentiating between these different classes we are assisted not only by the shape of the mihrab, but also by the various field designs, such for instance as the panels above and below the prayer field, the lanterns or pendants which hang from the centre of the niche, etc.
VARIOUS FORMS OF THE PRAYER-NICHE IN RUGS
| 1. | Persian | 11. | Kulah | 21. | Konieh and Meles |
| 2. | Persian | 12. | Kulah | 22. | Ladik |
| 3. | Persian and Konieh | 13. | Kulah | 23. | Ladik |
| 4. | Meshed and Saruk | 14. | Ghiordes | 24. | Kaisariyeh |
| 5. | Tabriz | 15. | Ghiordes | 25. | Bergama, Genghis, Daghestan, Bokhara |
| 6. | Kirman | 16. | Ghiordes | 26. | Bergama |
| 7. | Kirman | 17. | Ghiordes | 27. | Meles |
| 8. | Kirman and Kulah | 18. | Anatolian | 28. | Meles |
| 9. | Herez and Kulah | 19. | Anatolian | 29. | Daghestan and Kazak |
| 10. | Kulah | 20. | Konieh | 30. | Kazak and Beluchistan |
Single Panels.—When only one panel is used it is invariably above the prayer field. The Kulah nearly always has but one, the Anatolian generally, and the Ghiordes seldom.
Double Panels.—The Ghiordes nearly always has two, the Bergama generally, and the Kulah seldom.
Hanging pendants are always present in the Kaisarieh, frequently in the Ghiordes, and seldom in the Kulah.
Pillars are always present in the Kaisarieh, frequently in the Kulah, and only occasionally in the Ghiordes.