did it say mazda on it you sure that wasnt the back up key? back up keys had different numbers and usually didnt have rubber around them at all and sometimes were not even the same shape or size. i havent really look to into the spare keys as much

 

Not sure if it was a spare or not. It does have MAZDA on it though.

 

like i said i just know about a few things about them and which primary key were used when but you can check out that like your self and check to see which key it is http://foxed.ca/foxed/index.php?page=rx7manual