vermiculte

[arturo0161]

Hi I am trying to get started on building my brick oven but the only place that i have found vermiculite or perlite is home depot and they only have one type of each . is there a certain brand or a certain grain that I should be looking for and where can I get it Or can i use what they have at Home depot ?
I must also add that I have never laid a brick in my life but this looks like a fun project .