Earthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.The oldest rocks on Earth were formed about 3.8 billion years ago.arthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.
The first step to energy efficiency in your kitchen is to consider your appliances, and appliances with the ENERGY STARÂ® seal of approval are always the most energy efficient. Convection ovens also make a difference. The heated air is continuously circulated which reduces cook times as well as the temperatures required. On average you'll use 20% less energy a month running your convection oven, as compared to a standard oven.
A convection fan will dry out the oven much quicker, so it's best to bake cookies or bread without the convection on. Most convection ovens have the option to turn the fan on or off, so you can choose the right baking environment.