Specific heat capacity and thermal conductivity of slate

Painted stones have made life in Wigton happier during lockdown. Mrs B painted this slate in the greenhouse on a sunny day. When I moved it, I noticed that not only was the top surface hot but the bottom was too. The surface of slate is dark and absorbs heat radiation well. It has a specific heat capacity of 760 J/kg K https://www.engineeringtoolbox.com/specific-heat-solids-d_154.html This is the same as some of the metals I test in the lab so it certainly heats up quickly. The thermal conductivity is also quite good at 2 W/m K https://www.engineeringtoolbox.com/thermal-conductivity-d_429.html I had fun looking at other building materials for comparison. Brick is less good at conducting. I waited for another sunny day and went to find out if slates deeper down the pile, and out of direct sunlight, would feel warm. this was the case, showing that thermal energy was able to conduct quite a long way.