Ruling on touching the mushaf by one in a state of ritual impurity through a barrier?

Question:
Is the cover of the mushaf a barrier for the mushaf if I want to read the Noble Qur'an while I am not in a state of ritual purity?
If the cover is separate, not the attached leather, if the cover is separate like a chair, there is no harm; sitting on the chair and looking at it is fine. However, the cover itself that is attached to the Qur'an and bound with it must not be touched while in a state of impurity; ritual purity is required. But if it is separate, such as placing it on a chair to look at it, or having something on one's hands that covers them, there is no harm in case of need.