Question Summary:
Are leather or other halal animal skins halal for use as a prayer mat?

Question Detail:

Are leather or other halal animal skins halal for use as a prayer mat? Mainly for thier durability and long lasting usage.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
 
Leather from the skin of any animal, with the exception of the skin of human beings and pigs becomes pure upon tanning. It is permissible to use such tanned skin as a prayer mat.[1]
 
And Allah Ta’āla Knows Best
Muhammad Haris Siddiqui
Student Darul Iftaa
Australia 
Checked and Approved by,
Mufti Ebrahim Desai.