To be regarded as a jewel a gemstone must be rare and beautiful and durable enough to withstand handling and use. Not only diamonds, rubies, sapphires and emeralds can be classified as gemstones, aquamarine, peridot, amethyst and pearls are also gemstones. Rocks such as lapis lazuli and organic substances such as amber are considered to be semi-precious stones.

In its natural state a mineral gemstone is referred to as a rough stone. Some gemstones are made from minerals found in rocks or gravels and other gemstones such as amber, pearl and coral are organic in nature. Organic gems are usually polished, carved, or drilled as beads. Crystals are beautiful in their natural state and they too are polished and faceted to show off their beauty.

There are more than three thousands natural minerals, but less than a hundred are commonly used as gemstones. Some gemstones are manufactured as imitations of other gemstones. For example, cubic zirconia is an imitation of diamond. It copies the look of the diamond but does not possess its makeup.

A simple cut for a stone is cabochon which has a polished domed-shaped top and a flat or rounded base. Cabochon stones are often centerpieces in antique jewelry. Today most gemstones are cut to create a number of flat surfaces called facets. Faceting helps to reflect light by throwing flashes of colour in a play of brilliant light which enhances the sparkle of the stone.

There is a fine and often overlapping line that divides precious and semi-precious gemstones. An example of a blurred line would be amethyst which was once considered a precious stone but today although still a beautiful jewel, amethyst is considered semi-precious because its rarity has been decreased due to the large amounts of deposits of amethyst discovered in Brazil and Uruguay in the 19th century.

Today, due to their exquisite sought after appeal and rarity diamonds, rubies, emeralds, sapphires, opals and pearls are still classified as precious although these precious gems have different grades. For example, machine cut diamonds with little visual appeal can be purchased at low end prices but are still sought after because they are diamonds. Semi-precious stones and crystals with grade A value are made into high end jewellery with high end prices. Gem prices can fluctuate or as in the case of diamonds, be quite stable. Generally, larger gemstones have a higher carat price than smaller stones but the demand for certain sizes can also affect prices.

The appeal of gemstones, their beautiful colours and textures, their rarity and durability, have made them precious collectable objects throughout history. They have been seen as symbols of wealth and beauty and are offered as prestigious gifts but today gemstones are not just for the wealthy, they can be appreciated by anyone. There is a wide range of natural gemstones from all over the world. Even if a stone is not of the highest quality it can still be beautiful and well worth collecting. A collector can always find a stone or a handmade beaded necklace, bracelet or earring that fits the budget which will bring continued fascination and enjoyment.

Precious and semi-precious gem stones are also used in luxury art forms apart from jewelry.