Sunlight, moisture and other things that can have an affect on gemstones.

Some gemstones can have their colour and durability affected by sunlight. Stones such as Amethyst, Aquamarine, Citrine and Quartz can all become paler over time if constantly exposed to sunlight. Some stones such as Amber become darker with regular exposure to sunlight. This does not stop you from wearing these stones in pieces of jewellery on a daily basis, but it is important to store them in a safe place out of the sun (such as a jewellery box, or drawer). Correct storage can also eliminate the damage caused by heat. Jewellery and gemstones should not be subjected to rapid changes in temperature. Rapid temperature change can cause a gemstone to crack and also remove the natural moisture from certain stones causing irretrievable damage.
Other gemstones can also be affected by moisture. These are gems, primarily the 'organic' gems such as pearl and coral and also more pourris stones such as Opal. Salt water can also cause damage to your precious gemstones, so make sure when swimming in the sea all gem set jewellery is removed.