Re: Which rocklimestone,slate,sandstone,graniteretains the most heator/andcold?

Meg,

For a general introduction to mineral properties, here is an excellent guide put together by geologists in California: http://geology.csupomona.edu/alert/mineral/minerals.htm

As far as retaining heat/cold, the property you are thinking of is called "specific heat." The exact definition of this is "how much energy is required to heat a certain mass by a certain temperature." The units of this are joules (energy) per gram (mass) per degree (celsius, temperature). One of the highest commonly occurring specific heats is 4.2 J g-1 K-1, the specific heat of water. Dry air has a specific heat of 1.0 J g-1 K-1. So wet air takes much longer to warm than dry air. This is part of the reason foggy mornings are so cold!

Minerals, even very dense ones, generally have lower heat capacity than water: see this list here: http://www.engineeringtoolbox.com/specific-heat-solids-d_154.html

To learn more, you can read this interesting guide to mineral properties: http://webmineral.com/determin.shtml

Also, there is a ton of interesting material at geology.com, to satisfy all your curiosity!

Good luck!

--Edward H.