marble rocks in a fireplace?

September 7, 2006 8:31 PM

Can you put garden marble rocks in a fireplace?

I have some white and gray marble rocks that I had purchased in the garden section of my local home improvement store. They were in my flower beds, but now I am eyeing them to spruce up my drab dusty fireplace. I was thinking of lining the bottom of the fireplace with them below the grate and then loading it with kindling until it gets cold enough for a fire. This is for visual effect only, however I was wondering if I could actually leave it like that for the first fire. Is marble heat safe? I want to be sure they won't explode or anything. I would probably scoop them out and ditch them with the ashes, but they would look pretty until then.

posted by kgn2507 to Home & Garden (4 answers total)

Generally speaking you want to avoid sedimentary rock in fires, as water can be trapped between the layers. If it turns to steam, worst case, it explodes spraying shrapnel and embers into your room. Best case, it just splits open.

Marble is metamorphic, but porous. I'd make sure the rock was bone dry before putting it in a fire. You might try drying the rocks out in your oven at 150 degrees overnight first. That should dry out the rocks without breaking them. Turn off the oven and let them cool at their own rate.
posted by plinth at 8:39 PM on September 7, 2006

I'd be concerned about whether it could stand up to thermal shock. If it's too thin, there's a danger of it breaking.
posted by Steven C. Den Beste at 9:24 PM on September 7, 2006

"Some marbles exhibit hysteretic behavior after repeated heating and cooling cycles. This hysteresis is typically evident by a bowing of the marble panels, and can normally be eliminated if the panels are of sufficient thickness. Research of the particular marble should be done to determine its vulnerability to this phenomenon."

Source. No clue as to the accuracy.
posted by devilsbrigade at 12:52 AM on September 8, 2006

sounds like you are using small pieces. should be ok. a waste of good marble, though.
posted by lester's sock puppet at 7:53 AM on September 8, 2006