An offer is easier to read when three levels are distinguished: area of origin, quarry name and trade name. Chahmorghi is documented in Dehbid district; Shayan’s official website identifies Bavanat. Both are in Fars.
A purchase record should retain these references together with block number, selection and photographs. Similar colour or a shared trade name does not prove that two batches come from the same face. This guide distinguishes trade names from places of origin.