Crystals have the ability to store energies. They can remember negative and positive energies and therefore they should be cleaned and recharged regularly every two weeks. If the gemstone lacks energy, it fades, becomes brittle and its radiance and effectiveness decreases. That is why regular cleaning and energizing is so important with gemstones. 

First and foremost, you should clean it thoroughly after you buy it and before you use it for the first time. This will ensure that no excess energy or false information from strangers is passed on to you.

What options there are for cleansing and recharging, you can find here.