Can this brick be used for building a firepit

Barbara, Thank you for inquiring on Pacific Clay Products. Currently, Lowe's stocks only a few colors of our brick, typically located in the masonry aisle of the store. Of those colors, there will not be any in a gray color. However, Lowe's can special order brick from us, in which a gray color is something we offer. As for your firepit, it is important to understand that the outside shell of your firepit (what is visible to those sitting enjoying the fire) can be constructed with any of our brick. However, if a continuous fire were to be touching these brick, it would be too hot, and the brick could potentially explode. Therefore, in order to have a brick firepit, construct the shell, BUT, you must line the inside of your firepit with Pacific Clay Fire Brick. This is a specially made brick manufactured to withstand those temperatures. In fact, these Firebrick's are what's lined with most fireplaces in homes. Pacific Clay Firebrick can also be special ordered at the Pro Desk, unless you are lucky enough to have a store that stocks them. I hope this information helps. Please reach out should you need any further support. Thank you! P.S. I noticed your inquiry came across three separate times. So, I will use the same response for each. If one of your inquiry's goes unanswered, we will continue to get notifications. Best Regards.