I am considering purchasing a solar room for my home. I would like to capitalize on as much passive solar energy that I can.  One recommendation is to install a pea stone heat sink in the cement floor and use a quarry tile for the flooring. Any other suggestions? 

http://www.thenaturalhome.com/heatstorage.htm

I'm considering these in my modern passive solar home. Could look pretty cool.

Deb,

The pea stone being used as the heat storage material(heat sink) does not need to be exactly that material. What is important is that you have two factors in place:

1) Enough mass(pea stone/concrete/etc.) to be able to absorb enough heat to keep the room from overheating during the day
2) Enough insulation to prevent loss of the heat to the surrounding earth.

The amounts of these need to be calculated and need to be appropriate for your location(lattitude, elevaton, % of sunny days, degree-days) and the amount/orientation of windows in the room.

To summarize, unless you do the math, it is very easy to mess up and end up with a room that overheats or never gets warm enough. There needs to be a good balance between window area and thermal mass/insulation. If you are not familiar with this stuff, ask a pro to help calculate what you need.

Dave