Peridot
Peridot is gem-quality olivine. Olivine is a silicate mineral with
formula of (Mg, Fe)2SiO4. As peridot is the magnesium-rich variety
(forsterite) the formula approaches Mg2SiO4.
Appearance
Peridot is one of the few gemstones that occur in only one color, an
olive green. The intensity and tint of the green, however, depends on
how much iron is contained in the crystal structure, so the color of
individual peridot gems can vary from yellow- to olive- to
brownish-green. The most valued color is a dark olive-green.
Turmalin
Tourmaline is a crystal boron silicate mineral compounded with elements
such as aluminium, iron, magnesium, sodium, lithium, or potassium.
Tourmaline is classified as a semi-precious stone and the gemstone comes
in a wide variety of colors.
Usman International Gem provides a huge collection of varieties of Gemstones up to five carts