Although the words "mineral," "stone," "crystal," and "gemstone" are often used interchangeably, they actually imply different structural properties.
STONE (ROCK)
Rock or stone consists of a fixed combination of different minerals and does not have the specific chemical composition that you normally find in a mineral.
So a stone always contains several minerals and has a natural origin.
Three examples of rocks are:
• Lapis Lazuli: this consists of lazurite, calcite and pyrite.
• Jade: It is made up of two different minerals: jadeite and nephrite.
• Tiger's Eye: It consists of quartz with inclusions of fibers of the mineral crocidolite.
MINERAL
A mineral is a natural substance found in the Earth's crust and consists of a single chemical element or compound. It has a fixed crystal structure and can occur in various shapes, colors, and hardnesses. They are formed by geological processes, such as crystallization from molten rock, deposition from aqueous solutions, or biological precipitation. Although not all minerals have crystals visible to the naked eye, they do contain microscopic crystals.
There are a number of important characteristics that define a substance as a mineral: it must occur in nature, it must contain no organic substances, it must be a solid at room temperature, it must have a definite chemical composition and it must have an ordered internal structure.
Minerals form the basis of rocks and come in different shapes and colors.
5 well-known examples of minerals are:
• Hematite
• Pyrite
• Opal
• Quartz (mineral with a crystal structure)
• Amethyst (mineral with a crystal structure)
CRYSTAL
Most minerals occur in nature as crystals.
This creates specific features such as flat and smooth surfaces, angular shapes and refraction of light.
Crystals come in a variety of shapes and sizes and can be formed by both natural and synthetic processes.
The crystal structure can influence the physical properties of a mineral, such as color, luster, texture, and shape.
Popular crystals of one mineral are:
• Amethyst
• Rock crystal (clear quartz)
• Citrine
• Calcite
• Ruby.
• Emerald
GEMSTONE
A gemstone is a valuable mineral, crystal, or rock that is cut and polished for use in jewelry and decorative objects.
Gemstones are known for their beauty, clarity, color and rarity, and have been valued for centuries for their aesthetic and symbolic value.
The most famous gemstones are diamond, sapphire, emerald and ruby.
But some new, modern gemstones are:
• Morganite
• Tanzanite
• Aquamarine
• Peridot
• Tourmaline