Which state is known as "The Hawkeye State"?

Which state is known as "The Treasure State"? Which state is known as "The Gem State"? Which state is known as "The Equality State"? Which state is known as "The Cornhusker State"? Which state is known as "The Sunflower State"? Which state is known as "The Sooner State"? Which state is known as "The Natural State"? Which state is known as "The Pelican State"?