Amethysts are crystalline quartz that can be found in shades of purple, lilac or mauve. The gem was traditionally worn to guard against drunkenness and to instill a sober mind, even to protect one against poison. The word amethyst comes from the Greek “amethustos” meaning “a remedy for intoxication”.
The name diamond comes from the ancient Greek “adamas” meaning “unbreakable. They are gems that are made out of carbon. Diamonds are renowned as gems with superlative phusical qualities, and have the highest hardness and heat conductivity of any material. Making them one of the most desired gems available. A diamond's cost is based on the characteristics known as the "4 C's of Connoisseurship”. Clarity, Color and Cut (proportion) are the quality elements; which together with the Carat Weight determine the value of a stone. You may also consider a fancy colored diamond, which range in color and rarity from yellow, brown, colorless, blue, green, black, pink, orange, purple, and red. These colored diamonds can give your jewelry more character, more individuality and of course, more color!
The name emerald comes from the Greek 'smaragdos' via the Old French 'esmeralde’ and means essentially 'green gemstone'. It is a variety of the mineral beryl and is colored green by trace amounts of chromium. Emeralds, like diamonds, are graded using the four Cs of Connoisseurship. Stones that are clear to the eye of inclusions and have a vivid primary green hue command the highest prices. They are the most likely gemstone to be cut into cabochons, shaped and polished gems, rather than faceted.
Nature’s entire splendor seems to be reflected in the manifold opulence of fine Opals: fire and lightning, all the colors of the rainbow and the soft shine of far seas. The internal structure of the stone makes it diffract light and it therefore can take on many colors; ranging from clear and white, to all other colors under the rainbow it seems to reflect. The red and black opals are the rarest and the white and greens are the easiest to find. They vary in look from completely opaque to semi-transparent.
Rubies are the color of love – a clear, deep-red variety of corundum and are valued as a precious stone. Its name comes from ruber, Latin for red. Prices of rubies are primarily determined by their color. The brightest and most valuable "red" is often called pigeon blood-red and commands a huge premium over other rubies of similar quality. Clarity is also important in rubies, similar to diamonds; a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. The cut and carat are also important factors in determining the price.
The sapphire gem is another made from the mineral corundum. Trace amounts of other elements such as iron, titanium, or chromium which can give the gems their shades of blue, yellow, pink, purple, orange, or even greenish color. Hence the gems, rubies, emeralds and then your beautiful blue sapphires. The cost of natural sapphires varies depending on their size, cut, color and clarity, as well as their overall quality. Sapphires are usually found in Africa, Madagascar, Australia, Thailand, and Sri Lanka, and can even be found in North America in Montana.