A gemstone is the name given to a piece of mineral (or other rock or organic material) that after it has been cut and polished has been made into a piece of jewellery or another accessory. Although gemstones are commonly made from minerals, material such as jet or amber or rocks like lapis lazuli can also be utilised in the creation of gemstones. The majority of gemstones will be hard to the touch but depending on the piece of jewellery that is being created, some soft minerals are also utilised. Take a look at Moh’s Scale of Hardness to find out more about this.
Some other names for a gemstone include:
•    Gem / Fine Gem
•    Precious stone / Semi-precious stone
•    Jewel

How Are Gemstones Formed?
Even though the vast majority of gemstones are created below the surface of the earth, there are a number of different ways that the individual stones can be created. A great number of these precious stones are created when the minerals react with water that is found just below the surface of the earth and the minerals then dissolve. This process allows the minerals to form with gemstones like opals, agates and amethysts forming when the solution cools or evaporates.
Gems like malachite, azurite or turquoise are formed when water blends with rocks that are rich in copper. There is a strong history attached to turquoise gems with the ancient Egyptians regarding them to be an extremely precious gem. This means that turquoise gems have been around for 4,000 years or even longer!

Value of Gemstones
Much the same as you would expect from any other major industry, the price of gemstones is largely influenced by supply and demand.
One of the most important things for people when considering gemstones is the value and price for them but like in many industries, the laws of supply and demand are very much in place. This means that rare gems will carry a higher price tag.
For instance, a garnet is extremely stylish and attractive but it is not that rare, which means that its price tag is not too high. If you compared a garnet to a ruby of a similar size and condition, the ruby would always hold a higher price, simply because of the fact that it is a rare stone.

It is often difficult to place a true value on any particular gemstone because there is no uniform classification or measurement system in place. This is where gemstones differ from diamonds, which have been subject to a uniform measurement system since the 1950s. Traditionally, gemstones have been examined and evaluated by eye. When examining a gemstone, the four most important factors can be summed up in the four C’s, which are; colour, clarity, cut and carat.
Even though diamonds are one of the most prized possessions on Earth, there are actually a number of different gemstones that are rarer to find than diamonds. Some of the rarest gemstones you can find include:
•    Painite
•    Alexandrite
•    Tanzanite
•    Benitoite
•    Poudretteite
•    Grandiderite
•    Musgravite
•    Jeremejevite
•    Red Beryl