Assuming a furnace with a 78 percent efficiency, consumers should expect to pay roughly $12.96 per million BTUs of heat. While prices for gas and electricity vary over time and by region, gas furnaces typically cost much less to operate than electric furnaces or heaters.lectric space heaters all have AFUE ratings of 100 percent. Assuming an electric heater with 100 percent efficiency, homeowners should expect to pay roughly $34.32 per million BTUs of heat. Natural gas is generally sold in therms, where one therm is equal to 100,000 BTUs.
Rocks- A rock is made up of 2 or more minerals. You need minerals to make rocks, but you don't need rocks to make minerals. All rocks are made of minerals. Minerals- A mineral is composed of the same substance throughout.
A mineral is a naturally occurring substance, representable by a chemical formula, that is usually solid and inorganic, and has a crystal structure.It is different from a rock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition.his physical property is controlled by the chemical composition and crystalline structure of a mineral. A mineral's hardness is not necessarily constant for all sides, which is a function of its structure; crystallographic weakness renders some directions softer than others.