Question marked as
Yes. Amazon is an Authorized Apple reseller, and the Apple Store section on the Amazon.com website sells only original Apple products when directly sold by Amazon.
The case you posted a link for however, is not sold by Amazon, but by a third party seller on Amazon's Market Place. That cannot be guaranteed to be an original Apple case.
To verify the product is an Apple Original, make sure the sold and shipped by entries are set as Amazon only and nothing else.
For your link the blue case is not sold by Amazon, but the clay and black colors are.