Gemstones are any precious or semi-precious stones, whether as mined, or cut and polished.

The terms "gem" and "gemstone" mean any mineral or organic materia used for personal adornment, display, or object of art because it possesses beauty, rarity, and durability.

Of the 2,700 mineral species, only about 100 possess all these attributes. Silicates compose the largest group of gemstones; oxides and quartz compose the second largest.