Mining is one of WoW skills which can bring you more helpful as you are exploring in World of Warcraft. It can help you save WoW gold or gain it. Before you learn mining skill, you must understand it firstly.

Information of Mining

When you mine, you will find three main types of ingredients: metal, stones, and gems. Gems are rare and are used for better recipes for other professions, such as blacksmithing or engineering. Collect all the ingredients you find and keep them for later. Stones can be transformed by Blacksmiths and Engineers without the use of a forge. Many of these components can also be found from killing monsters or bought from other players. Yes, kill monster is not only gaining World of Warcraft gold but also some components now. If you are lacking WoW money, you are able to sell mines to gold of WoW.

When you mouse over the mineral vein, you will see a color showing whether you will gain skills by mining it.
Gray - You cannot increase your skill by mining.
Green - These mineral veins give you a fairly poor chance to increase your skill. You can still do it, but its going to take a lot of gathering/creation to up your skill with these mineral veins.
Yellow - These mineral veins give you a reduced chance of increasing your skill. Its still pretty reasonable to try to increase your skills with these mineral veins.
Orange - These mineral veins give you your best chance of increasing your skill. For many of the Professions making an orange item will always increase your skill.
Red - you cannot mine it yet. You need a higher mining skill.

After you have mastered the mining of a particular type of mineral, you will no longer gain skills by mining it. However, you can still use the minerals and stones you mine.