Onyx is a cryptocrystalline form of quartz.
Black diamonds, or Carbonado, are a natural polycrystalline diamond found in the Central African Republic and Brazil.
Diamond is without a doubt the most famous precious gemstone.
Citrine is a rare semi-precious stone, named after the French word for lemon, "citron".
Peridot is one of the few gemstones that occur in only one colour: basically an olive green.
Blue Topaz is a blue stone whose intensity varies from light to very intense blue.
Aquamarine is a very beautiful stone, transparent, light blue or sea-green.
Sapphire is one of the four precious gemstones.
Amethyst is a form of the mineral quartz and is usually purple, from pale lavender to a very deep reddish purple. But it can also occur in other colours, including green.
Garnets come in shades of red, from very light to deep red.
Rose quartz is a type of quartz which exhibits a pale pink to rose red hue.
Tourmalines come in various colours including black, brown, violet and green, as well as pink.
Sterling silver is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals, usually copper.
Gold is a highly sought-after and the most illustrious of the precious metal.
Platinum is the rarest of the precious metal and is used in jewellery - usually as a 90-95% alloy - for its inertness and shine.