Gemstone Formation

Most gemstones are in fact mineral crystals (non-mineral gems include pearls, coral, and amber) which form through a combination of natural chemicals (iron, copper, lead etc), reacting to heat and/or pressure. The chemicals present affect the resulting shape, hardness, cleavage, refractive index and color of the crystals formed.

The process of mineral crystal formation occurs naturally during the formation of rock, which can be divided into three categories:

Igneous rock - molten rock deep within the earth, wells up, creating intense pressure forcing the molten rock out through the earth's surface (lava) as this liquid cools the minerals crystals present can grow. Some examples - Diamond, Moonstone, Spinel & Zircon.

Metamorphic rocks - intense pressure and high temperatures can "recrystallize" the composition of rock, deep within the earth's crust, or through direct contact with hot magma. Emerald, jadeite, peridot, can be the result.