The Oxford English Dictionary suggests an alteration of Anglo–Norman pedoretés (classical Latin pæderot-), a kind of opal, rather than the Arabic word faridat, meaning "gemstone".

The Middle English Dictionary's entry on peridot includes several variations: peridod, peritot, pelidod and pilidod — other variants substitute y for letter i used here.

The intensity and tint of the green, however, depends on the percentage of iron in the crystal structure, so the color of individual peridot gems can vary from yellow, to olive, to brownish-green.

In rare cases, peridot may have a medium-dark toned, pure green with no secondary yellow hue or brown mask.

[6] The molecular structure of peridot consists of isomorphic olivine, silicate, magnesium and iron in an orthorhombic crystal system.

A peridot formed as a result of volcanic activity tends to contain higher concentrations of lithium, nickel and zinc than those found in meteorites.

[8][full citation needed] Olivine is an abundant mineral, but gem-quality peridot is rather rare due to its chemical instability on Earth's surface.

Increasing iron concentration ultimately forms the iron-rich end-member of the olivine solid solution series fayalite.

There is a superstition that it carries the gift of "inner radiance", sharpening the mind and opening it to new levels of awareness and growth, helping one to recognize and realize one's destiny and spiritual purpose.