central heating - a heating system in which air or water is heated at a central furnace and sent through the building via vents or pipes and radiators
exists and is an alternate of . Five physical characteristics of a mineral are: hardness, luster, diaphaneity, colour, and streak.
â¢A rock is a naturally occurring solid aggregate mass of mineral, or mineral-like matter â¢Most are aggregates of several different minerals âIndividual properties of the minerals are retained âSome rocks are composed of a single mineral â¢Example: limestone is an impure mass of the mineral calcite âSome rocks are made of non-mineral matter