Possible Clues:

• Blue birthstone
• Not the right bluestone for potato blight
• His paper can be turned into a jewel
• For the South, rent a priest till all is blue
• As it turns out, it's what you may pay for the rent of a priest till all is blue
• Thus might the South rent a priest till all is blue
• His paper beat stone
• His paper turned to stone
• County comprising a very soft stone
• Perhaps I changed colour