A natural gemstone is a mineral, stone, or organic matter
that can be cut and polished or otherwise treated for use as
jewelry or other ornament.
A precious gemstone has beauty, durability, and rarity,
whereas a semiprecious gemstone has only one or two of these
A gem is a gemstone that has been cut and polished.
Diamond, corundum (ruby and sapphire), beryl (emerald and
aquamarine), topaz, and opal are generally classed as precious
stones. All other gemstones are usually classed as
A mineral is any naturally formed homogeneous inorganic
A mineralogist is a person who studies the formation,
occurrence, properties, composition, and classification of
A gemologist is a person who has successfully completed
recognized courses in gemology (the science and study of
gemstones) and has proven skills in identifying and evaluating
A lapidary is a cutter, polisher, or engraver of precious