A rock is a natural solid substance that is composed of one or more minerals or other materials. Their structure is variable. For example, granite is a rock that contains minerals such as quartz, feldspar, and mica.
A mineral is a natural solid substance that has a definite chemical composition and a crystalline structure. For example, quartz is a mineral that consists of silicon and oxygen atoms arranged in a hexagonal pattern. Quartz, feldspar, calcite are good examples.
A crystal is a solid substance that has a regular and repeating pattern of atoms or molecules. A crystal can be a mineral or a synthetic material. For example, diamond is a crystal that is a mineral, while sugar is a crystal that is a synthetic material. Pyrite, fluorite and turquoise are further crystal examples.
A gemstone is a crystal or a mineral that is often considered rarer/scarce, beautiful, and durable. A gemstone can be used for jewelry or decoration. For example, ruby, emerald and sapphire are gemstones that are a crystal and a mineral, while pearl is a gemstone that is not a crystal or a mineral.
