Question: what is the difference between transparent soil or normail soil?

Nicola Lazenby answered on 18 Mar 2013:

Transparent soil is made from silica and oil….which is mixed together and has the air taken out. Because both of the materials reflect light by the same amounts the soil appears transparent! As the soil is heated, the amount of light which is reflected by the soil changes so that you can track the colour change as heat flows through the soil. This is something which you can’t do with the soil in your back garden!