The mihrab and mimber are of delicately carved white marble, and the ebony window shutters are inlaid with ivory and mother-of-pearl.
The mihrab and mimber are the most valuable things on the site.  
mnli hypothesis: The mihrab and mimber are the most valuable things on the site.   premise: The mihrab and mimber are of delicately carved white marble, and the ebony window shutters are inlaid with ivory and mother-of-pearl.