Marble slabs in the mass of a heater?

So my local reuse center currently has a bunch of used marble counter top bits and pieces.  I suspect it was donated by a company that installs counter tops.  Anyway the pieces are irregular in shape, size, color and condition.  It got me thinking it might be cool to fill my mass with some of this, perhaps put a layer down below the pipes.

I don't know the thermal qualities of Marble compared to the field stones I was planning to use.  As a laymen it seems that the marble would perform better as a thermal mass than the stones; but I have no idea what I'm talking about, hence this post...

Anyone use marble in their build?

Thanks
Rich

I'm pretty sure marble and granite, being denser than your average rock, would be better thermal mass. I would put some on the outside as well like tile. A big chunk would make a nice flat cooking surface. You could even make a little pizza oven. Might want to use the backside for that.

Edited to Add



Page 10 here http://www.eolss.net/ebooks/Sample%20Chapters/C08/E3-14-02-00.pdf

Found link to that here https://permies.com/t/27370/Gravel-Marble-Storing-Radiating-Heat

Check out Cast Iron (and copper but that's expensive)

Not sure about expansion and contraction.

Hi Rich;  I'm sure you want to use them.  Check out this chart. Granite is high up there.

Aren't there any nice enough pieces to sit upon?

Soapstone is used on wood stoves but I've never seen granite used. Maybe granite is prone to cracking when heated?

Just looked it up and it appears the answer is no. The only thing besides physical pressure which can crack granite is temperature extremes such as heating and plunging into water.

I just went to my "other" local reuse center and picked up 5 chunks of ugly marred up marble slabs for $20 bucks.  It's 1 5/8" thick and the longest one is 7ft long.  I think they'll be awesome heat sinks!  

So my plan is to build a shell out of bricks and mortar and line the inside with this marble.  I don't have enough to go all the way around but I do have some sandstone that I could use to fill in the gaps.   I plan to fill the remaining voids with pea gravel and/or sand.  I wish I could do cob but I'm in a sandy section of Michigan...

It looks like I'm gonna have to cut 4 inches of 2 of the lengths.  I've never cut marble before, a quick search suggests it's as simple as a diamond tipped blade.  I hope it's as simple as that...