Quartz is composed of the elements Silicon and oxygen.  In its pure state, quartz is colourless.  Small amounts of impurity atoms can yield a wide range of vivid colours.  Quartz is one of the most abundant minerals found in the Earth's crust.

Amethyst is produced by ferric oxide in quartz and people believe that wearing amethyst will help calm the wearer.  Some also believe that amethyst can help eliminate insomnia, improve memory and help develop wisdom.

Rose Quartz is believed to tone down one's temper and enhance one's interpersonal relationships.  It supposedly aids in bringing forth romance and creating a loving atmosphere for couples.

Turquoise is a rare and valuable ornamental stone.  Its name comes from the French pierre turquoise, meaning "Turkish stone", having been brought from Iran to Europe via Turkey.  It has been rpized for thousands of years, as evidenced from it use in an Egyptian tomb of c. 3000 B.C. and in the burial mask of Tutankhamun.

Jade and Jadeite are produced in high-pressure metamorphic rocks and the green is caused by the chromium.

Once thought to be the tears of the gods, pearls are used widely in jewellery and decorations.  They form in modern shellfish, such as mussels, as protection against natural or emplaced irritant (e.g. a piece of sand) within the soft parts.  Layers of nacre are secreted around the foreign body at a rate of 0.6mm per year. 

The nacre consists of aragonite crystals held together by conchiolin, a hornlike substance, and water.  Light reflecting from overlapping layers produces the characteristic lustre.

It is believed that the tiger-eye is a symbol of wealth and that those who are indecisive should carry or wear a piece to inspire self-confidence and courage for bold decision making.  It is also believed to help alleviate stress and enhance mental and physical ability.

Fengshui masters believe that moonstone helps one relieve tension and stress, cultivate harmonious relationships and achieve balance between the heart and mind.  It is also believed to possess healing abilities and boosts one's luck in romance.

Agate is a form of Chalcedony, with semi-concentric bands while moss agate is pale, translucent with dendritic moss or tree-like inclusions of iron oxide.  The translucent carnelian is orange-red and jasper.

Some believe that agate has the ability to deter unnecessary worries and brings the wearer better quality of sleep.  It is also believed to improve one's wealth and keeps the wearer optimistic.