(a) Granite is the most common igneous rock found on Earth's surface and is used to make many objects that they encounter in their day to day life. It is used to make countertops, floor tiles, paving stone, curbing, stair treads, building veneer, and cemetery monuments
(b) It doesn't have any color and is a tasteless gas. It is free of any kind of toxic, there is no smoke on burning and it has high calorific value. The gas is odorless. However, a chemical called mercaptan is added to it in small amounts to give it distinctive smell of eggs. The commercial sector uses natural gas to heat buildings and water, to operate refrigeration and cooling equipment, to cook, to dry clothes, and to provide outdoor lighting. Some consumers in the commercial sector also use natural gas as a fuel in combined heat and power systems.