It is an EE. Anyone who spells Americauna with an "I" is selling you EE's. If they come from a hatchery or feed store, they are EE's. Pure Ameraucana's (notice no I) only come from private breeders.
If you want pure Ameraucana's, it's best to go through the Ameraucana breeder directory to make sure you are getting pure Ameraucana's. Here's a link of the approved colors for Ameraucana's. Other colors are being worked on, like lavender, but they are not approved yet. http://www.ameraucana.org/scrapbook.html