Sapphire is another precious gemstone variety of the mineral corundum. Although blue is the best-known sapphire color, natural fancy sapphires also occur in yellow, purple, orange, and green colors, while "parti sapphires" show two or more colors. Red corundum stones are called rubies, not sapphires, while pink corundum may be classified either as ruby or sapphire.

Significant sapphire deposits are found in Australia, Afghanistan, Cambodia, Cameroon, China, Colombia, Ethiopia, India, Kenya, Laos, Madagascar, Malawi, Mozambique, Myanmar (formerly Burma), Nigeria, Rwanda, Sri Lanka, Tanzania, Thailand, the US, and Vietnam.

Though sapphires and rubies are often found in the same geographical settings, they generally have different geological formations.

Pink sapphires occur in shades from light to dark-pink and deepen in color as the quantity of chromium presence increases. The deeper its pink shade, the higher its monetary value.

Padparadscha, whose name is derived from the Sanskrit "padma ranga" (padma = lotus; ranga = color) is a delicate, light to medium-toned, pink-orange to orange-pink hue corundum, originally found in Sri Lanka, and also in deposits in Vietnam and parts of East Africa. Padparadscha sapphires are rare; the rarest of all being the natural variety, with no sign of artificial treatment.

A star sapphire is a type of sapphire that exhibits a star-like phenomenon known as asterism. At 1404.49 carats, The Star of Adam, mined in southern Sri Lanka, is claimed to be the largest blue star sapphire. The Black Star of Queensland, the second-largest star sapphire in the world, weighs 733 carats. The Star of India also mined in Sri Lanka and weighing 563.4 carats, is thought to be the third-largest star sapphire.