Seek these stones.

Agate: Agate is the stone for self-expression, creativity and good fortune.
Amethyst: Amethyst is associated with spiritual awareness, meditation, inner peace and healing.
Citrine: Citrine is a stone of success and prosperity, said to induce confidence and optimism in family and business relationships.
Fresh Water Pearls: Pearls are protective stones, believed to inspire purity, innocence and serenity.
Turquoise: Turquoise is a stone of peace, serenity and tranquility and is thought to increase meditation energy and wisdom.
Tiger's Eye: Tiger's eye is used for courage, confidence and protection.

Source: Semiprecious.com