Final answer:
L. Frank Baum, the author of 'The Wizard of Oz', is the correct answer as he created the Emerald City within the Land of Oz.
Step-by-step explanation:
The author who created an emerald city of literature and for whom the emerald would be an appropriate birthstone is L. Frank Baum. He is known for writing 'The Wizard of Oz,' where the Emerald City is a significant location within the magical land of Oz. This story was first told by Baum to children visiting his newspaper office and was later published in 1900. Baum's creation has become a classic in both literature and film and is often remembered for its vivid and imaginative depiction of the land of Oz.