Marble to place speakers on?


I remember reading a thread pertaining to placing your speakers on a marble surface. Up to this point I have been unable to find this thread on the audiogon site. So I am going to ask the question again. What should the demensions of my marble be? Height, Width, Depth, and Thickness. I appreciate your time.
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Refer to my post on audioreview.com/message/dcfourmid6/6975.html concerning stone platforms for floor-standers. MikE

Regarding purchasing your piece of marble. My wife suggested going to a cooking or kitchenware store. They supply marble for pastry rolling and it's very inexpensive. You can then cut to size with a tile cutter. Just a thought to save you money.
How would this slab of marble do for monitors? Any one have experience with it?
Kevint: Do you mean placing the marble between the floor and the stands? I have found a general belief in the forums that stands need to match the type of floor that they are used on. Heavy massive stands for floors that have very little give (such as slab floors) and rigid but lighter stands for floors that have more spring or give to them. I have used both types of stands on a floor (heavy plaster cement type material) that has very little give to it and found the first type of stand to offer superior sound. I started off with light rigid stands and did try placing marble between the floor (resting on top of the carpet and rug) and the bottom spikes of the stands. This setup made the system sound thin and bright. I tried it out with two different amps (ss and tube) and two sets of speakers (Castle Isis and Renaud Twins). I did not try spiking the marble to the floor though. I also tried the marble between the top plate of the stand and the speaker with a substance similar to Blue Tack as coupling on both sides of the marble (I did not try spikes). This setup sounded better than the first go round, but not good to my ear. Now that I have heavy massive stands I may give both setups another try. I still wonder if spiking the marble to the floor would be an improvement, but just do not have the materials available to try it out, plus the spikes would have to be affixed to the marble for safety and stability issues. Also the marble that I used is only 1" thick and I beleive that it is called shystic (sp) marble which is not at all pure in its makeup. If you try any of the combinations out I will be interested in the results that you achieve. The marble that I used was given to my wife's girlfriend for her patio. I have another 4' piece of the marble, but need to have it cut to size (we just want a pastry board cut from it and the remaining portion will be enough to try on the new stands and speakers). If it doesn't work I will just place my wife's orchids on the pieces. I doubt if I will get around to it anytime soon though.
Kevint, I have monitors and carpet and was having trouble levelling them so I bought 2 13"x13" floor tiles. I would be worried about raising your monitors too much because of the vertical position vis-a-vis your ears. I found that the sound is tighter and toeing in or out is easy. I also placed 10lb weights on the top of the monitors to kill some of the resonances. Cheers.